CA2031057C - Fabrication of optical components utilizing a laser - Google Patents
Fabrication of optical components utilizing a laserInfo
- Publication number
- CA2031057C CA2031057C CA002031057A CA2031057A CA2031057C CA 2031057 C CA2031057 C CA 2031057C CA 002031057 A CA002031057 A CA 002031057A CA 2031057 A CA2031057 A CA 2031057A CA 2031057 C CA2031057 C CA 2031057C
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- Prior art keywords
- site
- coupler
- optical
- fiber
- cladding
- Prior art date
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- Expired - Fee Related
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Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/2804—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers
- G02B6/2852—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers using tapping light guides arranged sidewardly, e.g. in a non-parallel relationship with respect to the bus light guides (light extraction or launching through cladding, with or without surface discontinuities, bent structures)
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/035—Aligning the laser beam
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/04—Automatically aligning, aiming or focusing the laser beam, e.g. using the back-scattered light
- B23K26/042—Automatically aligning the laser beam
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/12—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure
- B23K26/127—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure in an enclosure
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/245—Removing protective coverings of light guides before coupling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/30—Organic material
- B23K2103/42—Plastics
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/50—Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Mechanical Engineering (AREA)
- General Physics & Mathematics (AREA)
- Optical Couplings Of Light Guides (AREA)
- Optical Integrated Circuits (AREA)
Abstract
A method for fabricating optical components in the cladding of an optical fiber bus by the utilization of a laser. An excimer laser fabricates either an optical coupler opening or an optical mode scrambler by ablatively removing the cladding from the optical core of an optical fiber bus without damaging the optical core. Either coupler housing or a mode scrambler housing is attached to the optical fiber bus where the coupler or mode scrambler is to be fabricated.
The coupler housing is used to position the laser, secure and align a coupler fiber, and provide cavities for junction and cladding repair materials. The mode scrambler housing serves a similar purpose.
The coupler housing is used to position the laser, secure and align a coupler fiber, and provide cavities for junction and cladding repair materials. The mode scrambler housing serves a similar purpose.
Description
FABRICATION OF OPTICAL COMPONENTS UTILIZING A LASER
Technical Field This invention relates to the fabri~lion of optical components on an optical fiber bus and, in particular, to the fab. ;r~tiQr of reproducible o~el~;n~e 5 and patterns in the cladding of the optical fiber bus.
Back~round of the Invention The dimcr~ty of fabricating elr,c;cnl linear optical couplers on an optical fiber bus with highly controlled coupler ratios i.,~olves the complete removal of the cladding that surrounds the core of the optical fiber bus at the 10 coupler site as well as the precise placement of components at the coupler site.
The size, shape, position, and cleanliness of the cladding removal is critical in m~l ing a good linear optical coupler. Similar problems exist for the fabrication of optical mode scramblers. Further, it is i~ ,o lant that the optical fiber core not be dDm~ged during the cladding f~...o~al, and that the fabrication method 15 have a low cost per coupler or mode scrambler.
Mechd.-ical stripping methods are known for fab. ;-DRng coupler openings or mode scrambler patterns in the c~ lding~ These methods physically scrape the ~ ;ng from the core; however, such stripping often does not achieve the correct opening size and shape, and frequently damages 20 the core at the coupler or mode scrambler site, thus reducing the efficiency and strength of the optical fiber bus. Also, mechanical stripping techniques often leave cladding particles at the cou~l~r site, and further, do not allow for precise place,..e..t of components at the co.~ r site.
In addition to n~h~nical stripping, chemical etching has been 25 u~ili7.~d to r~-..o.~e the c~ ling from the optical core. Chemical etching techniques are limited bc~use of difficulties in achieving the correct ope~
size and shape, in accurately positioning the site defining mask, and in controlling the etching.
U. S. Patent 1J6~6,~52 ~I;sclos~s a method for fabricating optical 30 co~pl~rs that uses a laser to r~n-ove all but a thin layer of the cladding from two fibers and then uses heat to fuse the two fibers together. If the cladding normally p, c,J~tes the energy from the laser, the method requires the rl~d~ing to be treated or coated v~ith a s~bst~nce, such as a dye, to prevent the laser beam from pe--et~ -g the core of the fiber. Further, the laser beam 35 disadvantageously scans back and forth across the region to prevent total removal of the cladding.
21~3I~57 Mode scramblers have been fabricated in various ways. In U. S. Patent No. 4,676,594, a mode scrambler is achieved by making a deforn~tion such as a groove or a notch, on one side of the optical fiber bus orthogonal to the longitudinal axis. The patent d;~ losfs etching or mechanical 5 machining that prc ~ the groove or notch in the optical fiber cladding.
Another optical fiber mode scrambler is disclosed in, for example, the articles " Mess~ e~.lent of Rscebqnd Frequency Re~l.o-.se of Ml-lti~^ d e Fiber By Using A New Type of Mode Scrambler" by M. Tokuda et al. in " Electronic Letters," 3rd March 1977, Vol. 13, No. 5 at pages 146-147; and 10 " Transmission Characteristics Of M.~ dE W-Type Optical Fiber: Experimental Study Of The Effect Of The Intermediate Layer" by K. Mikoshiba et al. in " Applied Optics," Vol. 17, No. 17, Sept. 17, 1978, at pages 2836-2841. In these articles the disclosed mode scrambler includes an optical fiber comprising s~.;Gc sin~ dql se. ycn~ c bends.
Another form of an optical fiber mode scrambler is disclosed in, for example, the articles " Mode Scrambler For Optical Fibers" by M. Ikeda et al. in " Applied Optics," April 1977, Vol. 16, No. 4, at pages 1045-1049; and" Mode Scrambling Can Enhance Fiber Optic System Performance" by S. L. Sto~o~u~n in " Electronics," Feb. 24, 1981, Vol. 4, No. 54, at pages 163-166.
20 The mode scrambler in these articles comprises a few flbers in a bundle surrounded by a heat shrinkable tube which when shrunk causes fiber micro~ ing.
Star couplers for providing mode scrambling are also well known and comprise a first plurality of fibers interconnected to a second plurality of25 fibers by means of a mixing el~ t either comprising a planar waveguide section or formed by l-. ;Stil.g and fusing the twisted waveguides together. In this regard see, for example, U. S. Patent Nos. 4,362,357 and 4,449,783 or Fund~-nent~lc Of Optical Fiber Communications by M. K Barnoski, 2nd Edition, Academic Press, 1981, at pages 337-339.
U. S. Patent No. 4,749,248 discloses devices for co~pling optical power from and/or into optical fiber. This patent discloses the use of a photorefractive effect to change the refraction index of the core of a single mode fiber in order to transfer energy from bound modes to so-called t~mncl;ng leaklymodes (TL). The TL modes can then be re.~.o~ed from the cladding of the fiber 35 guide with the aid of a diel~l~c body in contact with the fiber at a do~ -slream point that has a ref ~ ~ ~tive index app~o~ tely equal to or greater than index - of refraction of the cladding. The phalorefi~ctive effect ~e~u;r~ that the core be doped with an appropriate dopant (e.g., Fe or Bi) and c~n~tr~ly cA~sE d to light of the appropriate wavelength. If the light is re...u.ed, the index of refraction reh.r,.s to its original state. In addition, this patent proposes the use 5 of a pholo~lD .t;c effect to vary the refractive index of the core using a light that induces stresses in the core.
The problem that exists in the art is to provide a technique for ma~ g effective coupl~rs and mode scramblers on an optical fiber bus by re..-~ .g the cladding from the optical core without ~mqgin~ the core and 10 also mqintqining the proper size, shape, and accuracy of ~,~;l;o---Summary of the Invention The afore.,-...lioned problem is solved and a technical advance is ed in the art for optical component fabrication by the ~ lior~ of a radiation source that ablatively re...û~es cladding from the surface of an optical 15 core without ~q~ g; .~ the optical core. Advanl~eûu~ly, the ablative re..~û~dl of cladding is used to form an optical mode scrambler pattern in the cl2~'~;ng or to form an optical coupler opening that allows an optical coupler to be fabricated. The radiation source is ~,refel ably an CAC;~e~ Iaser which is ~J. e~;ely aimed and whose power is carefully controlled. The ~tili7stion of an20 excimer laser in this manner has been found to allow for the fabrication of optical coupler o"...i--gs that are p. ~ -l~ lc cqfed have exact shapes, and areextremely clean of cladding particles. Also, the optical core is not damaged.
Advqnta~ usly, the ~ - ~dirl~ is of a polymer l..ate. ;al which can be easily ablatively re~ ed by the excimer laser; and the optical core is of a material 25 which cannot be sl~b~ .tially affected by the excimer laser.
In a ~ efe,, ed embodiment of the invention, a coupler housing is pre-positior ed on the optical bus and has several functions: (1) it provides an~ligr ment point for pOSi~iO~ g the laser over an a~.crlure in the housing at the co..pler site; (2) it provides a posit;o,-;.-g and ~ul~p~ I device for a coupler fiber 30 which exactly aligns the coupler fiber with the coupler site; (3) it provides vents that allow the housing at the co!lr'Er fiber and coupler site to be filled with a junction media that physically secur~s the coupler fiber to the housing and co ..~ -.icates light to or from the optical bus core; (4) it provides a cavity in the region opposite the coupler site on the optical bus to allow repair of any 35 cladding damage caused by the laser. Vents in this cavity allow the cavity to be filled with a material having s ~b~ y the same index of refraction as the cladding.
In another preferred embodiment of the invention, a mode scrambler housing is pre-positioned on the optical bus and has several functions: (1) it provides an alignment point for positioning the laser over an aperture in the housing at the 5 mode scrambler site; (2) it provides vents that allow the housing at the mode scrambler site to be filled with a material that preserves the light transmission characteristics of the optical bus core; (3) it provides a cavity in the region opposite the mode scrambler site on the optical bus to allow repair of any cladding damage caused by the laser. Vents in this cavity allow the cavity to be filled with a material 10 having substantially the same index of refraction as the cladding.
In accordance with one aspect of the invention there is provided a method of removing optical cladding from an optical core corresponding to a predefined pattern, comprising the steps of: forming radiation from a radiation source with an aperture to define said predefined pattern; focusing said formed radiation 15 onto a site on the surface of said optical cladding on said optical core; and controlling the energy level of said radiation source so as to substantially ablate all of said cladding corresponding to said predefined pattern at said site.
In accordance with another aspect of the invention there is provided apparatus for fabricating an optical component on an optical fiber, said optical fiber 20 having cladding surrounding an optical core, said apparatus comprising: a laser boring assembly; a housing attached to said optical fiber; said housing having a milling aperture that is aligned with a site on the surface of said cladding; said laser boring assembly having a radiation source and an aperture to define a predefined pattern at said site by forming radiation from said radiation source; lens for focusing said formed 25 radiation through said milling aperture onto said site; and controller for controlling the energy level of said radiation source so as to substantially ablate all of the cladding corresponding to said predefined pattern at said site.
In accordance with yet another aspect of the invention there is provided a coupler for communicating optical energy into or out of an optical fiber said optical 30 fiber being comprised of a core surrounded by a cladding, said coupler comprising an assembly adapted to be attached to said optical fiber and formed so as to define a) a first cavity that is in communication with a selected site on said fiber when said ~ 203 1 057 - 4a -housing is attached to said optical fiber, b) a milling aperture through which aradiation beam can be focused onto said site to ablatively remove a portion of said cl~ lin~ to expose the underlying portion of said core, c) a second cavity that is in communication with a region of said optical fiber opposite to said site when said housing is attached to said optical fiber, a coupler fiber alignment guide disposed in '~
said assembly in such a way that a coupler fiber inserted into said guide is aligned with said site, a coupler fiber inserted-into said alignment guide, a body of junction media filling said first cavity which allows for the communication of light between said coupler fiber and said site and which physically secures said coupler fiber to said assembly, and a body of repair medium filling said second cavity, said repair media having substantially the same index of refraction as said core.
Other and further aspects of the present invention will become apparent during the course of the following description and by reference to the accompanying drawing.
BriefDes~ Jtion of the Drawin~
Referring now to the drawing:
FIG.l illustrates an apparatus for fabricating an optical coupler in accordance with the present invention;
FIG. 2 illustrates a cross-sectional view of the apparatus of FIG.l;
FIG. 3 illustrates an apparatus for measuring the performance of fabricated couplers;
FIG. 4 illustrates a cross-sectional view of subassemblies 120 and 121 of FIG.l;
FIG.S illustrates an apparatus for fabricating an optical mode scrambler in accordance with present invention; and FIG.6 illustrates a cross-sectional view of the apparatus of FIG.S.
Detailed Description In accordance with the invention, a coupler opening or mode scrambler pattern is created in the cl~d~ing of an optical bus during optical component fabrication by ablatively removing the cladding using a radiation source such as an excimer laser. FIG.l illustrates an apparatus that fabricates couplers on an optical fiber bus in accordance with the invention, and FIG.S illustrates an apparatus that fabricates mode scramblers on the optical bus in accordance with the invention.
`_ ner~q~ce of the unique manner in which intense ultraviolet (UV) radiation effects a ~,ol~, ~ric material, an eY~ r laser re...o~es such a material by ablation rather than through thermal mechanisms such as melting or val.o ;~tion which are used by other types of lasers. When a pol~...er;c 5 material is irradiated by an excimer laser, numerous chemical bonds are broken. The resulting monomer products, regardless of their ~c:r~
c~ ~p~:~ on, have a larger specific volume than the original polymer, and the material explodes away from the irradiated region. A summary of the ablative mechanism of eYc;mer lasers can be found in the article entitlEd " Excimer 10 Lasers: An Emerging Technology in Mate.; l~ OC&a llg~ by T. A. 7not;ne~
" Lasers Focus-Electro-Opticc," May, 1987.
A cross-sect;~n ' view of the apparatus of FIG. 1 is illustrated in FIG. 2. As illustrated in FIG. 2, buffer 108 is removed from a region of opticalfiber bus 105, ex~ o~;-,g claddil.g 106. In this eYp~ced region, housing 15 s~b~eblies 120 and 121 are attached rP ~I~;ng in a ~c lio-. of the cladding of optical fiber bus 105 being totally sur. . dc d by these two s~bacsemblies.
Details of the s b~ccemblies are given in the cross-sectional view of FIG. 4. The s~b~ccemblies are secured to each other using conventional methods, such as gluing.
As illustrated in FlG. 2, subassembly 120 provides milling al,e. lure 111 which allows the laser beam of boring acsembly 119 to pass through s~ks~s-ml~ly 120 to coupler site 224. In addition, s~b^^-embly 120 provides fiber ~lig. ..~-.t guide 109 which supports and aligns coupler fiber 301 as illustrated in FIG. 3. The latter fiber is inserted into fiber alignment 25 guide 109 after coupler opening 213 is rO....cd in cladding 106. Also, s~b~s~...bly 120 includes index point 110, and controller 220 uses that index point to align boring assembly 119 with coupler site 224.
Once sub~cemblies 120 and 121 have been positioned and s~red onto optical fiber bus 105, boring assembly 119 is properly aligned with coupler30 site 224 by controller 220, using conventional ~ligrm~llt proccdures with reference to index point 110. Controller 220 co--trol~ PYeimer laser 201 to operate advantag~ou ,l~ at a wavelength of 193 nanometers (nm) to ablate cladding material 106 from optical fiber bus 105 without ~lqn-ag;rlg optical core 107. Laser 201 may adval~la~o.~ be a Questek Model 2660 laser. The 35 beam of laser 201 is advantageou~l~ first fc ...ed by ap&. lure 202 and then i...aged through a 4:1 telescope formed by lenses 203 and 204. The focal length ~031Q57 of the lenses is adjusted for a wavelength of 193 nm. An image one-fourth the o~ ;g;nal size of the ape. tur~ is formed at the focal point of lens 204. This image results in a predefined pattern being projected on coupler site 224. For example, a 1 millimeter (mm) circular a~,c. lure forms a circular image of 250 5 microns at the focal point of lens 204. Laser 201 is operated in the pulse mode.
The energy density at the coupler site is ad~ .tageou .l~ in the range of S to 10 milli~Joules/mm2. At a repetition rate of one puls~J~ec., app o~ ~ly 40 to 80 pulses are required to produce circular holes with diameters of 250 microns and 625 microns, r~"e.li~e4 Optical core 107 is 1 mm in ~i~meter;
10 cladding 106 is a 10-15 micron thick organic cladding; and buffer 108 is a 200 micron thick organic co~ting Illustratively, the optical core is glass, and cladding 106 is n.~O....ated acrylate.
After coupler opening 213 has been fo ...ed, coupler fiber 301 is inserted into fiber alignment guide 109 as illuslrdted in FIG. 3. After insertion 15 of the coupler fiber, junction media 302 is injected into junction cavity 212(ihu~lrdted in FIG. 2), completely fflling the junction cavity. If light is to be extracted from coupler Gp~..;..b 213, the junction media has a higher index of refraction than core 107. If light is to be launched from the coupler fiber intocore 107 via the coupler opening, the junction media has a higher index of 20 refr~ct;Qn than cladding 106. The junction media is injected into junction cavity 212 via a,~,c. hJrC 111 as illustrated in FIG. 2, and the air in the cavity is exhausted through exit vent 115. As illusl~ ated in FIG. 3, junction media 302 not only l- ~-.. lc light to or from coupler fiber 301 but also physically secures the portion of coupler fiber 301 that extends from fiber slignment guide 109 into 25 junction cavity 212.
During the ablation of coupler opening 213 by laser 201, some of the energy is transferred through core 107 d~ ;-.p the cladding on core 107 opposite couplc r opening 213. This impairment is illustrated as damaged region 214. Having s--bsta-~t;~lly the same index of refr ~ lion as cladding 106, 30 repair material 309 is injected into cavib 218 via fill vent 217. The air from repair cavity 218 is exhausted via vent 216. FIG. 3 illu~lrates that a damaged portion of buffer 108 can also be repaired with material 308.
FIG. 3 illustrates a measuring apparatus for dete....... l.;ng the ~e. rc ...ance of fabricated couplers. Optical fiber bus 105 is excited with 35 randomly polarized light from laser 305 which iLu~lr&li~el~ iS a 633 nm HeNe laser with a 10 milliwatt rated output. A measurement is performed to -- determine the amount of light conducted from bus 105 to coupler fiber 301 via coupler opening 213 and junction media 302. The m~re...e..l of the coupler power output is made in rerere~ ce to the light rece:~ed at far end detector 306.
This rere~e..ce is r~ 5 ~J-~able since the amount of power extracted is very small 5 compared with the total power in optical flber bus 10S. The reading at far endtector 306 is the 0 dB reference, and the light out of the coupler is a dB
r~din~ relative to the power exiting optical flber bus 105. The 250 micron eter holes result in a power output at coupler opening 213 in the range of -24 dB to -2S dB.
FIG. S illustrates an apparatus that fabricates an optical mode scrambler on an optical fiber bus in ~ ~rdance with the invention. As illustrated in the cross sect;on~l view of FIG. 6, buffer S08 is r~.no~ed from aregion of optical fiber bus 505, ~ ,l,o;,h.g cladding 506. Optical fiber bus S05 is similar to optical fiber bus 105. In this ~ .osed region, housing 15 SUb? ~ ;emblies 520 and 521 are attached r~ ~ ~ll;. g in a portion of the cladding of optical fiber bus 505 being totally surrounded by these two suba~s_...l,l;~s. The sul,assolnblies are secured to each other using con~.nli~..al methods, such as gluing.
Once s~b~ ~mblies 520 and 521 have been positioned and ecured 20 onto optical fiber bus 505, boring ascembly 519 is properly aligned with modescrambler site 624 by co--lroller 620, using conventional alignment procedurec with reference to index point 510. S ~b~cce~nbly 520 provides milling aperture 511 which allows the laser beam of boring s~e~nbly 519 to pass through subsccemhly 520 to mode scrambler site 624. This laser beam projects 25 a predefined pattern onto site 624. FIG. 6 illustrates that mode scrambler pattern 613 has already been ~blsted by boring ~sembly 519. Mode scr~m~ler pattern 613 may be similar to one of those disclosed in U. S. Patent No. 4,676,594. After mode scrambler pattern 613 is r~ ...ed, cavity 612 is filled with a material whose index of refraction is less than the cladding to prescr.e 30 the light transmission characteristics of optical bus 505. During the ablative process, part of the energy ~lril~il.g mode scrambler site 624 passes through core 507 and damages the cladding illu~ll ated as damaged region 614. To repair damaged region 614, subassembly 521 provides repair cavity 618 which is filled with a naterial having substantially the same refractive index as 35 cladding 506.
21~ 57 Boring assembly 519 is identical to boring P~em' ly 119 except that a~,e. Iure 602 forms the laser beam from laser 601 into a mode scrambler pattern. Laser 601 operates at similar energy levels and pulse rates as previousdescribed with respect to laser 201.
S - It is to be unde.~lood that the above-described embod;~ is merely illustrative of the principles of the invention and that other ar.z..ge..lents may be ~;sed by those skilled in the art without departing from the spirit and scope of the invention. Although an excimer laser has been used to ablative re...o~e cladding, another suitable radiation source can be used.
10 Other housings can be en~;~ged by those skilled in the art. An apparatus in ~r~rda. ce with the invention is not limited to the re..~o~al of cladding for mqk;ng only coupler openings or mode scrambler patterns but can be used to make other types of optic. l cc ..pO..~
Technical Field This invention relates to the fabri~lion of optical components on an optical fiber bus and, in particular, to the fab. ;r~tiQr of reproducible o~el~;n~e 5 and patterns in the cladding of the optical fiber bus.
Back~round of the Invention The dimcr~ty of fabricating elr,c;cnl linear optical couplers on an optical fiber bus with highly controlled coupler ratios i.,~olves the complete removal of the cladding that surrounds the core of the optical fiber bus at the 10 coupler site as well as the precise placement of components at the coupler site.
The size, shape, position, and cleanliness of the cladding removal is critical in m~l ing a good linear optical coupler. Similar problems exist for the fabrication of optical mode scramblers. Further, it is i~ ,o lant that the optical fiber core not be dDm~ged during the cladding f~...o~al, and that the fabrication method 15 have a low cost per coupler or mode scrambler.
Mechd.-ical stripping methods are known for fab. ;-DRng coupler openings or mode scrambler patterns in the c~ lding~ These methods physically scrape the ~ ;ng from the core; however, such stripping often does not achieve the correct opening size and shape, and frequently damages 20 the core at the coupler or mode scrambler site, thus reducing the efficiency and strength of the optical fiber bus. Also, mechanical stripping techniques often leave cladding particles at the cou~l~r site, and further, do not allow for precise place,..e..t of components at the co.~ r site.
In addition to n~h~nical stripping, chemical etching has been 25 u~ili7.~d to r~-..o.~e the c~ ling from the optical core. Chemical etching techniques are limited bc~use of difficulties in achieving the correct ope~
size and shape, in accurately positioning the site defining mask, and in controlling the etching.
U. S. Patent 1J6~6,~52 ~I;sclos~s a method for fabricating optical 30 co~pl~rs that uses a laser to r~n-ove all but a thin layer of the cladding from two fibers and then uses heat to fuse the two fibers together. If the cladding normally p, c,J~tes the energy from the laser, the method requires the rl~d~ing to be treated or coated v~ith a s~bst~nce, such as a dye, to prevent the laser beam from pe--et~ -g the core of the fiber. Further, the laser beam 35 disadvantageously scans back and forth across the region to prevent total removal of the cladding.
21~3I~57 Mode scramblers have been fabricated in various ways. In U. S. Patent No. 4,676,594, a mode scrambler is achieved by making a deforn~tion such as a groove or a notch, on one side of the optical fiber bus orthogonal to the longitudinal axis. The patent d;~ losfs etching or mechanical 5 machining that prc ~ the groove or notch in the optical fiber cladding.
Another optical fiber mode scrambler is disclosed in, for example, the articles " Mess~ e~.lent of Rscebqnd Frequency Re~l.o-.se of Ml-lti~^ d e Fiber By Using A New Type of Mode Scrambler" by M. Tokuda et al. in " Electronic Letters," 3rd March 1977, Vol. 13, No. 5 at pages 146-147; and 10 " Transmission Characteristics Of M.~ dE W-Type Optical Fiber: Experimental Study Of The Effect Of The Intermediate Layer" by K. Mikoshiba et al. in " Applied Optics," Vol. 17, No. 17, Sept. 17, 1978, at pages 2836-2841. In these articles the disclosed mode scrambler includes an optical fiber comprising s~.;Gc sin~ dql se. ycn~ c bends.
Another form of an optical fiber mode scrambler is disclosed in, for example, the articles " Mode Scrambler For Optical Fibers" by M. Ikeda et al. in " Applied Optics," April 1977, Vol. 16, No. 4, at pages 1045-1049; and" Mode Scrambling Can Enhance Fiber Optic System Performance" by S. L. Sto~o~u~n in " Electronics," Feb. 24, 1981, Vol. 4, No. 54, at pages 163-166.
20 The mode scrambler in these articles comprises a few flbers in a bundle surrounded by a heat shrinkable tube which when shrunk causes fiber micro~ ing.
Star couplers for providing mode scrambling are also well known and comprise a first plurality of fibers interconnected to a second plurality of25 fibers by means of a mixing el~ t either comprising a planar waveguide section or formed by l-. ;Stil.g and fusing the twisted waveguides together. In this regard see, for example, U. S. Patent Nos. 4,362,357 and 4,449,783 or Fund~-nent~lc Of Optical Fiber Communications by M. K Barnoski, 2nd Edition, Academic Press, 1981, at pages 337-339.
U. S. Patent No. 4,749,248 discloses devices for co~pling optical power from and/or into optical fiber. This patent discloses the use of a photorefractive effect to change the refraction index of the core of a single mode fiber in order to transfer energy from bound modes to so-called t~mncl;ng leaklymodes (TL). The TL modes can then be re.~.o~ed from the cladding of the fiber 35 guide with the aid of a diel~l~c body in contact with the fiber at a do~ -slream point that has a ref ~ ~ ~tive index app~o~ tely equal to or greater than index - of refraction of the cladding. The phalorefi~ctive effect ~e~u;r~ that the core be doped with an appropriate dopant (e.g., Fe or Bi) and c~n~tr~ly cA~sE d to light of the appropriate wavelength. If the light is re...u.ed, the index of refraction reh.r,.s to its original state. In addition, this patent proposes the use 5 of a pholo~lD .t;c effect to vary the refractive index of the core using a light that induces stresses in the core.
The problem that exists in the art is to provide a technique for ma~ g effective coupl~rs and mode scramblers on an optical fiber bus by re..-~ .g the cladding from the optical core without ~mqgin~ the core and 10 also mqintqining the proper size, shape, and accuracy of ~,~;l;o---Summary of the Invention The afore.,-...lioned problem is solved and a technical advance is ed in the art for optical component fabrication by the ~ lior~ of a radiation source that ablatively re...û~es cladding from the surface of an optical 15 core without ~q~ g; .~ the optical core. Advanl~eûu~ly, the ablative re..~û~dl of cladding is used to form an optical mode scrambler pattern in the cl2~'~;ng or to form an optical coupler opening that allows an optical coupler to be fabricated. The radiation source is ~,refel ably an CAC;~e~ Iaser which is ~J. e~;ely aimed and whose power is carefully controlled. The ~tili7stion of an20 excimer laser in this manner has been found to allow for the fabrication of optical coupler o"...i--gs that are p. ~ -l~ lc cqfed have exact shapes, and areextremely clean of cladding particles. Also, the optical core is not damaged.
Advqnta~ usly, the ~ - ~dirl~ is of a polymer l..ate. ;al which can be easily ablatively re~ ed by the excimer laser; and the optical core is of a material 25 which cannot be sl~b~ .tially affected by the excimer laser.
In a ~ efe,, ed embodiment of the invention, a coupler housing is pre-positior ed on the optical bus and has several functions: (1) it provides an~ligr ment point for pOSi~iO~ g the laser over an a~.crlure in the housing at the co..pler site; (2) it provides a posit;o,-;.-g and ~ul~p~ I device for a coupler fiber 30 which exactly aligns the coupler fiber with the coupler site; (3) it provides vents that allow the housing at the co!lr'Er fiber and coupler site to be filled with a junction media that physically secur~s the coupler fiber to the housing and co ..~ -.icates light to or from the optical bus core; (4) it provides a cavity in the region opposite the coupler site on the optical bus to allow repair of any 35 cladding damage caused by the laser. Vents in this cavity allow the cavity to be filled with a material having s ~b~ y the same index of refraction as the cladding.
In another preferred embodiment of the invention, a mode scrambler housing is pre-positioned on the optical bus and has several functions: (1) it provides an alignment point for positioning the laser over an aperture in the housing at the 5 mode scrambler site; (2) it provides vents that allow the housing at the mode scrambler site to be filled with a material that preserves the light transmission characteristics of the optical bus core; (3) it provides a cavity in the region opposite the mode scrambler site on the optical bus to allow repair of any cladding damage caused by the laser. Vents in this cavity allow the cavity to be filled with a material 10 having substantially the same index of refraction as the cladding.
In accordance with one aspect of the invention there is provided a method of removing optical cladding from an optical core corresponding to a predefined pattern, comprising the steps of: forming radiation from a radiation source with an aperture to define said predefined pattern; focusing said formed radiation 15 onto a site on the surface of said optical cladding on said optical core; and controlling the energy level of said radiation source so as to substantially ablate all of said cladding corresponding to said predefined pattern at said site.
In accordance with another aspect of the invention there is provided apparatus for fabricating an optical component on an optical fiber, said optical fiber 20 having cladding surrounding an optical core, said apparatus comprising: a laser boring assembly; a housing attached to said optical fiber; said housing having a milling aperture that is aligned with a site on the surface of said cladding; said laser boring assembly having a radiation source and an aperture to define a predefined pattern at said site by forming radiation from said radiation source; lens for focusing said formed 25 radiation through said milling aperture onto said site; and controller for controlling the energy level of said radiation source so as to substantially ablate all of the cladding corresponding to said predefined pattern at said site.
In accordance with yet another aspect of the invention there is provided a coupler for communicating optical energy into or out of an optical fiber said optical 30 fiber being comprised of a core surrounded by a cladding, said coupler comprising an assembly adapted to be attached to said optical fiber and formed so as to define a) a first cavity that is in communication with a selected site on said fiber when said ~ 203 1 057 - 4a -housing is attached to said optical fiber, b) a milling aperture through which aradiation beam can be focused onto said site to ablatively remove a portion of said cl~ lin~ to expose the underlying portion of said core, c) a second cavity that is in communication with a region of said optical fiber opposite to said site when said housing is attached to said optical fiber, a coupler fiber alignment guide disposed in '~
said assembly in such a way that a coupler fiber inserted into said guide is aligned with said site, a coupler fiber inserted-into said alignment guide, a body of junction media filling said first cavity which allows for the communication of light between said coupler fiber and said site and which physically secures said coupler fiber to said assembly, and a body of repair medium filling said second cavity, said repair media having substantially the same index of refraction as said core.
Other and further aspects of the present invention will become apparent during the course of the following description and by reference to the accompanying drawing.
BriefDes~ Jtion of the Drawin~
Referring now to the drawing:
FIG.l illustrates an apparatus for fabricating an optical coupler in accordance with the present invention;
FIG. 2 illustrates a cross-sectional view of the apparatus of FIG.l;
FIG. 3 illustrates an apparatus for measuring the performance of fabricated couplers;
FIG. 4 illustrates a cross-sectional view of subassemblies 120 and 121 of FIG.l;
FIG.S illustrates an apparatus for fabricating an optical mode scrambler in accordance with present invention; and FIG.6 illustrates a cross-sectional view of the apparatus of FIG.S.
Detailed Description In accordance with the invention, a coupler opening or mode scrambler pattern is created in the cl~d~ing of an optical bus during optical component fabrication by ablatively removing the cladding using a radiation source such as an excimer laser. FIG.l illustrates an apparatus that fabricates couplers on an optical fiber bus in accordance with the invention, and FIG.S illustrates an apparatus that fabricates mode scramblers on the optical bus in accordance with the invention.
`_ ner~q~ce of the unique manner in which intense ultraviolet (UV) radiation effects a ~,ol~, ~ric material, an eY~ r laser re...o~es such a material by ablation rather than through thermal mechanisms such as melting or val.o ;~tion which are used by other types of lasers. When a pol~...er;c 5 material is irradiated by an excimer laser, numerous chemical bonds are broken. The resulting monomer products, regardless of their ~c:r~
c~ ~p~:~ on, have a larger specific volume than the original polymer, and the material explodes away from the irradiated region. A summary of the ablative mechanism of eYc;mer lasers can be found in the article entitlEd " Excimer 10 Lasers: An Emerging Technology in Mate.; l~ OC&a llg~ by T. A. 7not;ne~
" Lasers Focus-Electro-Opticc," May, 1987.
A cross-sect;~n ' view of the apparatus of FIG. 1 is illustrated in FIG. 2. As illustrated in FIG. 2, buffer 108 is removed from a region of opticalfiber bus 105, ex~ o~;-,g claddil.g 106. In this eYp~ced region, housing 15 s~b~eblies 120 and 121 are attached rP ~I~;ng in a ~c lio-. of the cladding of optical fiber bus 105 being totally sur. . dc d by these two s~bacsemblies.
Details of the s b~ccemblies are given in the cross-sectional view of FIG. 4. The s~b~ccemblies are secured to each other using conventional methods, such as gluing.
As illustrated in FlG. 2, subassembly 120 provides milling al,e. lure 111 which allows the laser beam of boring acsembly 119 to pass through s~ks~s-ml~ly 120 to coupler site 224. In addition, s~b^^-embly 120 provides fiber ~lig. ..~-.t guide 109 which supports and aligns coupler fiber 301 as illustrated in FIG. 3. The latter fiber is inserted into fiber alignment 25 guide 109 after coupler opening 213 is rO....cd in cladding 106. Also, s~b~s~...bly 120 includes index point 110, and controller 220 uses that index point to align boring assembly 119 with coupler site 224.
Once sub~cemblies 120 and 121 have been positioned and s~red onto optical fiber bus 105, boring assembly 119 is properly aligned with coupler30 site 224 by controller 220, using conventional ~ligrm~llt proccdures with reference to index point 110. Controller 220 co--trol~ PYeimer laser 201 to operate advantag~ou ,l~ at a wavelength of 193 nanometers (nm) to ablate cladding material 106 from optical fiber bus 105 without ~lqn-ag;rlg optical core 107. Laser 201 may adval~la~o.~ be a Questek Model 2660 laser. The 35 beam of laser 201 is advantageou~l~ first fc ...ed by ap&. lure 202 and then i...aged through a 4:1 telescope formed by lenses 203 and 204. The focal length ~031Q57 of the lenses is adjusted for a wavelength of 193 nm. An image one-fourth the o~ ;g;nal size of the ape. tur~ is formed at the focal point of lens 204. This image results in a predefined pattern being projected on coupler site 224. For example, a 1 millimeter (mm) circular a~,c. lure forms a circular image of 250 5 microns at the focal point of lens 204. Laser 201 is operated in the pulse mode.
The energy density at the coupler site is ad~ .tageou .l~ in the range of S to 10 milli~Joules/mm2. At a repetition rate of one puls~J~ec., app o~ ~ly 40 to 80 pulses are required to produce circular holes with diameters of 250 microns and 625 microns, r~"e.li~e4 Optical core 107 is 1 mm in ~i~meter;
10 cladding 106 is a 10-15 micron thick organic cladding; and buffer 108 is a 200 micron thick organic co~ting Illustratively, the optical core is glass, and cladding 106 is n.~O....ated acrylate.
After coupler opening 213 has been fo ...ed, coupler fiber 301 is inserted into fiber alignment guide 109 as illuslrdted in FIG. 3. After insertion 15 of the coupler fiber, junction media 302 is injected into junction cavity 212(ihu~lrdted in FIG. 2), completely fflling the junction cavity. If light is to be extracted from coupler Gp~..;..b 213, the junction media has a higher index of refraction than core 107. If light is to be launched from the coupler fiber intocore 107 via the coupler opening, the junction media has a higher index of 20 refr~ct;Qn than cladding 106. The junction media is injected into junction cavity 212 via a,~,c. hJrC 111 as illustrated in FIG. 2, and the air in the cavity is exhausted through exit vent 115. As illusl~ ated in FIG. 3, junction media 302 not only l- ~-.. lc light to or from coupler fiber 301 but also physically secures the portion of coupler fiber 301 that extends from fiber slignment guide 109 into 25 junction cavity 212.
During the ablation of coupler opening 213 by laser 201, some of the energy is transferred through core 107 d~ ;-.p the cladding on core 107 opposite couplc r opening 213. This impairment is illustrated as damaged region 214. Having s--bsta-~t;~lly the same index of refr ~ lion as cladding 106, 30 repair material 309 is injected into cavib 218 via fill vent 217. The air from repair cavity 218 is exhausted via vent 216. FIG. 3 illu~lrates that a damaged portion of buffer 108 can also be repaired with material 308.
FIG. 3 illustrates a measuring apparatus for dete....... l.;ng the ~e. rc ...ance of fabricated couplers. Optical fiber bus 105 is excited with 35 randomly polarized light from laser 305 which iLu~lr&li~el~ iS a 633 nm HeNe laser with a 10 milliwatt rated output. A measurement is performed to -- determine the amount of light conducted from bus 105 to coupler fiber 301 via coupler opening 213 and junction media 302. The m~re...e..l of the coupler power output is made in rerere~ ce to the light rece:~ed at far end detector 306.
This rere~e..ce is r~ 5 ~J-~able since the amount of power extracted is very small 5 compared with the total power in optical flber bus 10S. The reading at far endtector 306 is the 0 dB reference, and the light out of the coupler is a dB
r~din~ relative to the power exiting optical flber bus 105. The 250 micron eter holes result in a power output at coupler opening 213 in the range of -24 dB to -2S dB.
FIG. S illustrates an apparatus that fabricates an optical mode scrambler on an optical fiber bus in ~ ~rdance with the invention. As illustrated in the cross sect;on~l view of FIG. 6, buffer S08 is r~.no~ed from aregion of optical fiber bus 505, ~ ,l,o;,h.g cladding 506. Optical fiber bus S05 is similar to optical fiber bus 105. In this ~ .osed region, housing 15 SUb? ~ ;emblies 520 and 521 are attached r~ ~ ~ll;. g in a portion of the cladding of optical fiber bus 505 being totally surrounded by these two suba~s_...l,l;~s. The sul,assolnblies are secured to each other using con~.nli~..al methods, such as gluing.
Once s~b~ ~mblies 520 and 521 have been positioned and ecured 20 onto optical fiber bus 505, boring ascembly 519 is properly aligned with modescrambler site 624 by co--lroller 620, using conventional alignment procedurec with reference to index point 510. S ~b~cce~nbly 520 provides milling aperture 511 which allows the laser beam of boring s~e~nbly 519 to pass through subsccemhly 520 to mode scrambler site 624. This laser beam projects 25 a predefined pattern onto site 624. FIG. 6 illustrates that mode scrambler pattern 613 has already been ~blsted by boring ~sembly 519. Mode scr~m~ler pattern 613 may be similar to one of those disclosed in U. S. Patent No. 4,676,594. After mode scrambler pattern 613 is r~ ...ed, cavity 612 is filled with a material whose index of refraction is less than the cladding to prescr.e 30 the light transmission characteristics of optical bus 505. During the ablative process, part of the energy ~lril~il.g mode scrambler site 624 passes through core 507 and damages the cladding illu~ll ated as damaged region 614. To repair damaged region 614, subassembly 521 provides repair cavity 618 which is filled with a naterial having substantially the same refractive index as 35 cladding 506.
21~ 57 Boring assembly 519 is identical to boring P~em' ly 119 except that a~,e. Iure 602 forms the laser beam from laser 601 into a mode scrambler pattern. Laser 601 operates at similar energy levels and pulse rates as previousdescribed with respect to laser 201.
S - It is to be unde.~lood that the above-described embod;~ is merely illustrative of the principles of the invention and that other ar.z..ge..lents may be ~;sed by those skilled in the art without departing from the spirit and scope of the invention. Although an excimer laser has been used to ablative re...o~e cladding, another suitable radiation source can be used.
10 Other housings can be en~;~ged by those skilled in the art. An apparatus in ~r~rda. ce with the invention is not limited to the re..~o~al of cladding for mqk;ng only coupler openings or mode scrambler patterns but can be used to make other types of optic. l cc ..pO..~
Claims (20)
1. Apparatus for fabricating an optical component on an optical fiber, said optical fiber having cladding surrounding an optical core, said apparatus comprising:
a laser boring assembly;
a housing attached to said optical fiber;
said housing having a milling aperture that is aligned with a site on the surface of said cladding;
said laser boring assembly having a radiation source and an aperture to define a predefined pattern at said site by forming radiation from said radiation source;
lens for focusing said formed radiation through said milling aperture onto said site; and controller for controlling the energy level of said radiation source so as to substantially ablate all of the cladding corresponding to said predefined pattern at said site.
a laser boring assembly;
a housing attached to said optical fiber;
said housing having a milling aperture that is aligned with a site on the surface of said cladding;
said laser boring assembly having a radiation source and an aperture to define a predefined pattern at said site by forming radiation from said radiation source;
lens for focusing said formed radiation through said milling aperture onto said site; and controller for controlling the energy level of said radiation source so as to substantially ablate all of the cladding corresponding to said predefined pattern at said site.
2. The apparatus of claim 1 wherein said optical component is an optical coupler and said radiation ablates a coupler opening at said site.
3. The apparatus of claim 2 wherein said optical core is of a material which is substantially unaffected by said radiation at said energy level.
4. The apparatus of claim 3 wherein said radiation source is an excimer laser.
5. The apparatus of claim 3 wherein said housing comprises coupler fiber alignment guide for accepting a coupler fiber to provide proper alignment of said coupler fiber with said coupler opening thereby resulting in said optical coupler.
6. The apparatus of claim 5 wherein said housing further comprises a first and second subassembly with said first subassembly having said milling aperture and said coupler fiber alignment guide and said first and second subassemblies forming a cavity surrounding said site so that a junction media can be injected into said cavity through said milling aperture after the ablation of the cladding at said coupler site and said junction media allowing for the communication of light between said coupler fiber and said coupler opening.
7. The apparatus of claim 6 wherein said coupler fiber alignment guide allows said coupler fiber to extend out of said coupler fiber alignment guide and said junction media adheres to the extended part of said coupler fiber to physically secure said coupler fiber to said first subassembly.
8. The apparatus of claim 7 wherein said second subassembly positioned on the opposite side of said optical core from said site and said second subassembly forming a cavity surrounding a portion of said cladding opposite said site and having a fill vent so that a repair media can be injectedinto said cavity through said fill vent after the ablation of the cladding at said site so that said repair media can repair damage to said portion of said cladding opposite of said site resulting from radiation transmitted through said optical core from said site.
9. The apparatus of claim 8 wherein said controller determines said energy level by pulsing said laser 40 to 80 times to form said site at pulse repetition rate of one pulse per second with an energy of 5 to 10 milli-Joules/square millimeter at said coupler opening.
10. The apparatus of claim 1 wherein said optical component is an optical mode scrambler and said radiation ablates a mode scrambler pattern at said site.
11. The apparatus of claim 10 wherein said optical core is of a material which is substantially unaffected by said radiation at said energy level.
12. The apparatus of claim 11 wherein said radiation source is an excimer laser.
13. The apparatus of claim 12 wherein said housing further comprises a first and second subassembly with said first subassembly having said milling aperture and said first and second subassemblies forming a cavity surrounding said site so that a junction media can be injected into said cavity through said milling aperture after the ablation of the cladding at said site and said junction media preserving the light transmission characteristics of said optical core.
14. The apparatus of claim 13 wherein said housing comprises a first and second subassembly and said second subassembly positioned on the opposite side of said optical core from said site and said second subassembly forming a cavity surrounding a portion of said cladding opposite said site and having a fill vent so that a repair media can be injected into said cavity through said fill vent after the ablation of the cladding at said site so that said repair media can repair damage to said portion of said cladding opposite of said site resulting from radiation transmitted through said optical core from said site.
15. The apparatus of claim 14 wherein said controller determines said energy level by pulsing said laser 40 to 80 times to form said site at pulse repetition rate of one pulse per second with an energy of 5 to 10 milli-Joules/square millimeter at said coupler opening.
16. A housing adapted for use in the fabrication of an optical coupler of an optical fiber, said housing comprising:
an assembly formed so as to define (a) a first cavity that is in communication with a selected site on said fiber when said housing is attached to said optical fiber, (b) a milling aperture through which a radiation beam can be focused onto said site, (c) a second cavity that is in communication witha region of said optical fiber opposite to said site when said housing is attached to said optical fiber; and a coupler fiber alignment guide disposed in said assembly in such a way that a coupler fiber inserted into said guide is aligned with said site.
an assembly formed so as to define (a) a first cavity that is in communication with a selected site on said fiber when said housing is attached to said optical fiber, (b) a milling aperture through which a radiation beam can be focused onto said site, (c) a second cavity that is in communication witha region of said optical fiber opposite to said site when said housing is attached to said optical fiber; and a coupler fiber alignment guide disposed in said assembly in such a way that a coupler fiber inserted into said guide is aligned with said site.
17. The invention of claim 16 wherein said assembly is further formed so as to define a fill vent through which media can be injected into said second cavity.
18. A coupler for communicating optical energy into or out of an optical fiber said optical fiber being comprised of a core surrounded by a cladding, said coupler comprising:
an assembly adapted to be attached to said optical fiber and formed so as to define (a) a first cavity that is in communication with a selected site on said fiber when said housing is attached to said optical fiber,(b) a milling aperture through which a radiation beam can be focused onto said site to ablatively remove a portion of said cladding to expose the underlying portion of said core (c) a second cavity that is in communication with a region of said optical fiber opposite to said site when said housing is attached to said optical fiber;
a coupler fiber alignment guide disposed in said assembly in such a way that a coupler fiber inserted into said guide is aligned with said site;
a coupler fiber inserted into said alignment guide;
a body of junction media filling said first cavity which allows for the communication of light between said coupler fiber and said site and which physically secures said coupler fiber to said assembly; and a body of repair medium filling said second cavity, said repair media having substantially the same index of refraction as said core.
an assembly adapted to be attached to said optical fiber and formed so as to define (a) a first cavity that is in communication with a selected site on said fiber when said housing is attached to said optical fiber,(b) a milling aperture through which a radiation beam can be focused onto said site to ablatively remove a portion of said cladding to expose the underlying portion of said core (c) a second cavity that is in communication with a region of said optical fiber opposite to said site when said housing is attached to said optical fiber;
a coupler fiber alignment guide disposed in said assembly in such a way that a coupler fiber inserted into said guide is aligned with said site;
a coupler fiber inserted into said alignment guide;
a body of junction media filling said first cavity which allows for the communication of light between said coupler fiber and said site and which physically secures said coupler fiber to said assembly; and a body of repair medium filling said second cavity, said repair media having substantially the same index of refraction as said core.
19. A housing adapted for use with a boring assembly in the fabrication of an optical coupler on an optical fiber, said optical fiber havingcladding surrounding an optical core and said boring assembly including means for forming and focusing radiation onto a site on said cladding, said housing comprising:
first and second subassemblies attachable to said optical fiber to form said housing;
said first subassembly a milling aperture that is aligned with said site on the surface of said cladding and adaptable for said formed and focused radiation to pass through said milling aperture;
said first subassembly further comprising a coupler fiber alignment guide for accepting a coupler fiber to provide proper alignment of said coupler fiber with said coupler opening;
said first and second subassemblies further forming a cavity surrounding said site and adaptable so that a junction media can be injected into said cavity through said milling aperture after the ablation of the cladding at said coupler site and said junction media allowing for the communication of light between said coupler fiber and said site and said coupler fiber alignment guide allows said coupler fiber to extend out of said coupler fiber alignment guide; and said second subassembly adaptable for being positioned on the opposite side of said optical core from said coupler site and said second subassembly forming another cavity surrounding a portion of said cladding opposite said site and having a fill vent and adaptable so that a repair media can be injected into said other cavity through said fill vent after the ablationof the cladding at said site.
first and second subassemblies attachable to said optical fiber to form said housing;
said first subassembly a milling aperture that is aligned with said site on the surface of said cladding and adaptable for said formed and focused radiation to pass through said milling aperture;
said first subassembly further comprising a coupler fiber alignment guide for accepting a coupler fiber to provide proper alignment of said coupler fiber with said coupler opening;
said first and second subassemblies further forming a cavity surrounding said site and adaptable so that a junction media can be injected into said cavity through said milling aperture after the ablation of the cladding at said coupler site and said junction media allowing for the communication of light between said coupler fiber and said site and said coupler fiber alignment guide allows said coupler fiber to extend out of said coupler fiber alignment guide; and said second subassembly adaptable for being positioned on the opposite side of said optical core from said coupler site and said second subassembly forming another cavity surrounding a portion of said cladding opposite said site and having a fill vent and adaptable so that a repair media can be injected into said other cavity through said fill vent after the ablationof the cladding at said site.
20. A housing adapted for use with a boring assembly in the fabrication of an optical mode scrambler on an optical fiber and said optical fiber has cladding surrounding an optical core and said boring assembly including means for forming and focusing radiation onto a site on said cladding, and said housing comprising:
first and second subassemblies attachable to said optical fiber to form said housing;
said first subassembly comprising a milling aperture that is aligned with said site on the surface of said cladding and adaptable for said formed and focused radiation to pass through said milling aperture;
said first and second subassemblies further forming a cavity surrounding said site and adaptable so that a junction media can be injected into said cavity through said milling aperture; and said second subassembly adaptable for being positioned on the opposite side of said optical core from said mode scrambler site and said second subassembly forming another cavity surrounding a portion of said cladding opposite said mode scrambler site and having a fill vent and adaptable so that a repair media can be injected into said other cavity through said fill vent after the ablation of the cladding at said site.
first and second subassemblies attachable to said optical fiber to form said housing;
said first subassembly comprising a milling aperture that is aligned with said site on the surface of said cladding and adaptable for said formed and focused radiation to pass through said milling aperture;
said first and second subassemblies further forming a cavity surrounding said site and adaptable so that a junction media can be injected into said cavity through said milling aperture; and said second subassembly adaptable for being positioned on the opposite side of said optical core from said mode scrambler site and said second subassembly forming another cavity surrounding a portion of said cladding opposite said mode scrambler site and having a fill vent and adaptable so that a repair media can be injected into said other cavity through said fill vent after the ablation of the cladding at said site.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/454,603 US4989936A (en) | 1989-12-21 | 1989-12-21 | Fabrication of optical components utilizing a laser |
| US454,603 | 1989-12-21 |
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|---|---|
| CA2031057A1 CA2031057A1 (en) | 1991-06-22 |
| CA2031057C true CA2031057C (en) | 1996-02-13 |
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| CA002031057A Expired - Fee Related CA2031057C (en) | 1989-12-21 | 1990-11-28 | Fabrication of optical components utilizing a laser |
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| EP (1) | EP0435468B1 (en) |
| CA (1) | CA2031057C (en) |
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| US5130512A (en) * | 1989-12-21 | 1992-07-14 | Coyle Jr Richard J | Fabrication of optical components utilizing a laser |
| US5101090A (en) * | 1990-11-19 | 1992-03-31 | At&T Bell Laboratories | Methods and apparatus for making optical fiber couplers |
| US6904201B1 (en) * | 2001-05-09 | 2005-06-07 | Intel Corporation | Phase-controlled fiber Bragg gratings and manufacturing methods |
| DE10136507A1 (en) | 2001-07-17 | 2003-04-03 | Zeiss Carl | Geometric beam splitter and process for its manufacture |
| JP3982551B2 (en) * | 2003-03-10 | 2007-09-26 | セイコーエプソン株式会社 | Optical component housing and projector |
| EP1645897B1 (en) * | 2004-10-08 | 2009-06-17 | Avago Technologies Fiber IP (Singapore) Pte. Ltd. | Method of fabrication of an optical or electronic module comprising a plastic housing |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3310587A1 (en) * | 1983-03-23 | 1984-09-27 | Siemens AG, 1000 Berlin und 8000 München | LIGHTWAVE LEAD BRANCHING, ITS APPLICATION AND METHOD FOR THEIR PRODUCTION |
| US4598039A (en) * | 1984-07-02 | 1986-07-01 | At&T Bell Laboratories | Formation of features in optical material |
| WO1986001303A1 (en) * | 1984-08-13 | 1986-02-27 | United Technologies Corporation | Method for impressing grating within fiber optics |
| US4676594A (en) * | 1984-11-16 | 1987-06-30 | American Telephone And Telegraph Company | Optical fiber mode scrambler |
| US4626652A (en) * | 1985-03-21 | 1986-12-02 | Honeywell Inc. | Method and means of removing claddings from optical fibers |
| US4726644A (en) * | 1985-07-08 | 1988-02-23 | General Dynamics Electronics Division | RF frequency multiplexed fiber optic data bus |
| US4749248A (en) * | 1985-11-06 | 1988-06-07 | American Telephone And Telegraph Company At&T Bell Laboratories | Device for tapping radiation from, or injecting radiation into, single made optical fiber, and communication system comprising same |
| GB2189901B (en) * | 1986-04-25 | 1989-12-06 | Stc Plc | Laser induced optical fibre grating devices. |
| US4784452A (en) * | 1986-08-01 | 1988-11-15 | Ensign-Bickford Optics Co. | Optical fiber coupler |
| JPS63163308A (en) * | 1986-12-25 | 1988-07-06 | Furukawa Electric Co Ltd:The | Optical element and its manufacture |
| DE3718402A1 (en) * | 1987-06-02 | 1988-12-22 | Ceram Optec Dr Neuberger Kg | Optical fibre decladding method |
| US4861136A (en) * | 1987-07-15 | 1989-08-29 | American Telephone And Telegraph Company | Optical communication systems using fabry-perot cavities |
| US4898444A (en) * | 1988-11-30 | 1990-02-06 | American Telephone And Telegraph Company | Non-invasive optical coupler |
-
1989
- 1989-12-21 US US07/454,603 patent/US4989936A/en not_active Expired - Lifetime
-
1990
- 1990-11-28 CA CA002031057A patent/CA2031057C/en not_active Expired - Fee Related
- 1990-11-29 EP EP90313002A patent/EP0435468B1/en not_active Expired - Lifetime
- 1990-11-29 DE DE69025048T patent/DE69025048T2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| DE69025048D1 (en) | 1996-03-07 |
| EP0435468B1 (en) | 1996-01-24 |
| EP0435468A3 (en) | 1992-04-29 |
| CA2031057A1 (en) | 1991-06-22 |
| DE69025048T2 (en) | 1996-08-29 |
| US4989936A (en) | 1991-02-05 |
| EP0435468A2 (en) | 1991-07-03 |
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| EEER | Examination request | ||
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