CA2351535A1 - Optical multiplexer/demultiplexer using resonant grating filters - Google Patents
Optical multiplexer/demultiplexer using resonant grating filters Download PDFInfo
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- CA2351535A1 CA2351535A1 CA002351535A CA2351535A CA2351535A1 CA 2351535 A1 CA2351535 A1 CA 2351535A1 CA 002351535 A CA002351535 A CA 002351535A CA 2351535 A CA2351535 A CA 2351535A CA 2351535 A1 CA2351535 A1 CA 2351535A1
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/20—Filters
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- 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
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/12007—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/10—Beam splitting or combining systems
- G02B27/1086—Beam splitting or combining systems operating by diffraction only
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/18—Diffraction gratings
- G02B5/1861—Reflection gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials
-
- 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
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
- G02B6/29305—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide
- G02B6/29307—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide components assembled in or forming a solid transparent unitary block, e.g. for facilitating component alignment
-
- 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
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
- G02B6/29305—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide
- G02B6/2931—Diffractive element operating in reflection
-
- 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
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
- G02B6/29305—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide
- G02B6/29311—Diffractive element operating in transmission
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- 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
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29346—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by wave or beam interference
- G02B6/29361—Interference filters, e.g. multilayer coatings, thin film filters, dichroic splitters or mirrors based on multilayers, WDM filters
- G02B6/29362—Serial cascade of filters or filtering operations, e.g. for a large number of channels
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- 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
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
- G02B6/2938—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/02—Wavelength-division multiplex systems
Abstract
A wavelength division multiplex/demultiplexer (WDM) has a plurality of narro w- band zeroth order resonant grating filters (10a-10e) to multiplex or demultiplex multiple wavelengths that have very close channel spacing. In on e embodiment, a plurality of these filters (10a-10e) are assembled in a block (20) in parallel and at an angle to a propagation axis to reflect signals fo r a plurality of discrete frequency channels. The block spacing material (21) can be liquid or solid. In another embodiment, the angular orientation of th e resonant grating filters (10f-10g) is varied slightly to provide reflected signals for the plurality of discrete frequency channels. Crosstalk between channels can be reduced by reflecting each signal three times. Individual filters can be of binary structure or a sinusoidal grating (16) and can be made using thin film techniques.
Description
USING RESONANT GRATII~fG FILTERS
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
This invention was made with Government support under Contract No. DE-AC05-960822464 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.
DESCRIPTION OF THE BACKGROUND ART
Wavelength Division Multiplexing (WDM) is a technique for separating light into optical waves of differing frequencies to increase the number of channels and the amount of information that can be transmitted through a single fiber optic system. The 20 bandwidth or frequency response of a single channel is limited by both the laser source and the detector. Therefore, in order to increase the total bandwidth of the communication system, additional wavelength channels are used. The realistic bandwidth (approximately 30 GHz) of a fiber optic system is limited by both the absorption and dispersion characteristics of optical fiber.
In order to utilize as much of this bandwidth as possible, each wavelength channel should be closely spaced. For example, a channel spacing of 0.8nm around 1550nm corresponds to a single channel bandwidth of 0.4nm, which is approximately 50 GHz.
Tomlinson, III, U.S. Pat. No. 4,111,824, shows a fiber optic system and a diffraction grating for performing the multiplexing/demultiplexing function. Wagner, U.S. Pat. No.
4,474,424, discloses the use of several interference filters integrated into a single device for reflecting light at different angles. This device is said to improve upon the channel spacing and bandwidth of Tomlinson.
Scobey, U.S. Pat. No. 5,583,683, discloses the use of resonant interference filters, which pass only a single wavelength of light and reflect other wavelengths. The light is reflected back and Earth within a solid block filter element, exiting at different points to distribute the light in several beams of different wavelengths.
Mizrahi, U.S. Pat. No. 5,457,760, discloses arrays of optical filtering elements in the form of Bragg gratings to create a desired wavelength passband in an optical filter.
Optical signals from a demultiplexer are transmitted over a plurality of waveguides in the form of optical fibers or planar members.
Mashev and Popov in "Zero Order Anomaly of Dielectric Coated Gratings," Optics Communications, Vol. 55, No. 6 (15 October 1985) disclose a zeroth order diffraction grating which produces a resonance anomaly, in which light: at the zeroth order is reflected. This operation can be tuned to provide a narrow-band wavelength filter. The grating is provided by a three-layer dielectric grating having an element of material with grooves in which the dielectric is air, and the crating is then coated with a third dielectric material.
Magnusson et al . , U. S . Pat . No . 5 ,, 216 , 680 , discloses the use of a resonant filter constructed with thin film materials for providing a tuneable laser beam. In Nfagnusson, the light signal is used to operate an optical switch.
Current wavelength division multiplexing/demultiplexing (WDM) systems are expensive to manufacture, have high optical losses, and can suffer from inadequate performance.
SUMMARY OF THE INVENTION
The invention relates to a solid state filter assembly incorporating a plurality of resonant grating filters for demultiplexing or multiplexing optical signals to process a plurality of discrete wavelengths.
The invention in incorporated in an optical signal multiplexer/demultiplexer that comprises a plurality of resonant grating filters. This allows all wavelength (frequency) channels to be separated or combined in a single device. The deva.ce is distinguishable from other technologies in its use of resonant grating filters for selecting t:he desired wavelength.
Advantageous features include manufacturing ease, potential for WO 01/27b66 PCTIUS00/25345 extremely high throughput and performance, and ability to be integrated into an array or stack containing a large number of filters for selecting specific wavelengths.
The invention is more particularly exemplified in an optical device for operation as either a mult:iplexer or demultiplexer.
The device comprises a plurality of resonant grating filters arranged along a propagation axis which extends to a multiplexed optical channel for a plurality of optical signal frequencies.
The filters reflect optical signal: at respective resonant frequencies, and the filters transmit optical signals at frequencies other than their respective resonant frequencies along the propagation axis. The filters are each arranged at a non-perpendicular angle to the propacration axis to reflect the reflection signal between the propagation axis and a respective one of a plurality of discrete frequency channels provided for carrying optical signals having a plurality of respective discrete frequencies.
The filters of the present invention are preferably zeroth order diffraction grating filters. Such filters are further preferably narrow-band (potentially 1-;2 Angstroms bandwidth) with extremely high throughput. The filters can be replicated from a single master, are relatively inexpensive to mass produce, and can be integrated into high density arrays from discrete wavelength discrimination. The cente r wavelength of the narrow-band filter can also be tuned over a small range by altering one of the grating parameters tangle of incidence, index of refraction, grating period, etc.).
These and other obj ects of the present invention will become readily apparent from the following especification and from the drawings which are incorporated herein and which describe and illustrate several preferred embodiments of the invention. Such embodiments are not, however, exh<~ustive of all possible embodiments, and therefore reference should be made to the claims which follow the description for the legal scope of the invention.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
This invention was made with Government support under Contract No. DE-AC05-960822464 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.
DESCRIPTION OF THE BACKGROUND ART
Wavelength Division Multiplexing (WDM) is a technique for separating light into optical waves of differing frequencies to increase the number of channels and the amount of information that can be transmitted through a single fiber optic system. The 20 bandwidth or frequency response of a single channel is limited by both the laser source and the detector. Therefore, in order to increase the total bandwidth of the communication system, additional wavelength channels are used. The realistic bandwidth (approximately 30 GHz) of a fiber optic system is limited by both the absorption and dispersion characteristics of optical fiber.
In order to utilize as much of this bandwidth as possible, each wavelength channel should be closely spaced. For example, a channel spacing of 0.8nm around 1550nm corresponds to a single channel bandwidth of 0.4nm, which is approximately 50 GHz.
Tomlinson, III, U.S. Pat. No. 4,111,824, shows a fiber optic system and a diffraction grating for performing the multiplexing/demultiplexing function. Wagner, U.S. Pat. No.
4,474,424, discloses the use of several interference filters integrated into a single device for reflecting light at different angles. This device is said to improve upon the channel spacing and bandwidth of Tomlinson.
Scobey, U.S. Pat. No. 5,583,683, discloses the use of resonant interference filters, which pass only a single wavelength of light and reflect other wavelengths. The light is reflected back and Earth within a solid block filter element, exiting at different points to distribute the light in several beams of different wavelengths.
Mizrahi, U.S. Pat. No. 5,457,760, discloses arrays of optical filtering elements in the form of Bragg gratings to create a desired wavelength passband in an optical filter.
Optical signals from a demultiplexer are transmitted over a plurality of waveguides in the form of optical fibers or planar members.
Mashev and Popov in "Zero Order Anomaly of Dielectric Coated Gratings," Optics Communications, Vol. 55, No. 6 (15 October 1985) disclose a zeroth order diffraction grating which produces a resonance anomaly, in which light: at the zeroth order is reflected. This operation can be tuned to provide a narrow-band wavelength filter. The grating is provided by a three-layer dielectric grating having an element of material with grooves in which the dielectric is air, and the crating is then coated with a third dielectric material.
Magnusson et al . , U. S . Pat . No . 5 ,, 216 , 680 , discloses the use of a resonant filter constructed with thin film materials for providing a tuneable laser beam. In Nfagnusson, the light signal is used to operate an optical switch.
Current wavelength division multiplexing/demultiplexing (WDM) systems are expensive to manufacture, have high optical losses, and can suffer from inadequate performance.
SUMMARY OF THE INVENTION
The invention relates to a solid state filter assembly incorporating a plurality of resonant grating filters for demultiplexing or multiplexing optical signals to process a plurality of discrete wavelengths.
The invention in incorporated in an optical signal multiplexer/demultiplexer that comprises a plurality of resonant grating filters. This allows all wavelength (frequency) channels to be separated or combined in a single device. The deva.ce is distinguishable from other technologies in its use of resonant grating filters for selecting t:he desired wavelength.
Advantageous features include manufacturing ease, potential for WO 01/27b66 PCTIUS00/25345 extremely high throughput and performance, and ability to be integrated into an array or stack containing a large number of filters for selecting specific wavelengths.
The invention is more particularly exemplified in an optical device for operation as either a mult:iplexer or demultiplexer.
The device comprises a plurality of resonant grating filters arranged along a propagation axis which extends to a multiplexed optical channel for a plurality of optical signal frequencies.
The filters reflect optical signal: at respective resonant frequencies, and the filters transmit optical signals at frequencies other than their respective resonant frequencies along the propagation axis. The filters are each arranged at a non-perpendicular angle to the propacration axis to reflect the reflection signal between the propagation axis and a respective one of a plurality of discrete frequency channels provided for carrying optical signals having a plurality of respective discrete frequencies.
The filters of the present invention are preferably zeroth order diffraction grating filters. Such filters are further preferably narrow-band (potentially 1-;2 Angstroms bandwidth) with extremely high throughput. The filters can be replicated from a single master, are relatively inexpensive to mass produce, and can be integrated into high density arrays from discrete wavelength discrimination. The cente r wavelength of the narrow-band filter can also be tuned over a small range by altering one of the grating parameters tangle of incidence, index of refraction, grating period, etc.).
These and other obj ects of the present invention will become readily apparent from the following especification and from the drawings which are incorporated herein and which describe and illustrate several preferred embodiments of the invention. Such embodiments are not, however, exh<~ustive of all possible embodiments, and therefore reference should be made to the claims which follow the description for the legal scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective diagram of a first embodiment of an individual resonant grating filter of the prior art;
Fig. lA is refraction index diagram for the embodiment of Fig. l;
Fig. 2 is a perspective diagram of ~ second embodiment of an individual resonant grating filter of the prior art;
Fig. 2A is refraction index diagram for the embodiment of Fig. 2;
Fig. 3 is a first embodiment of a multiplexing/
demultiplexing device of the present invention incorporating a plurality of the filters seen in Fig. 1;
Fig. 4 is a second embodiment of a multiplexing/
demultiplexing device of the present invention;
Fig. 5A and Fig. 5B are reflectance vs. wavel.ength diagrams for the embodiment of Fig. 4.
Fig. 6 is a third embodiment of a multiplexing/
demultiplexing device of the present :invention;
Fig. 7A and Fig. 7B are reflectance vs. wavelength diagrams for the embodiment of Fig. 6; and Figs. 8A, 8B and 8C illustrate a method of making a plurality of the filters of the type in Fig. 2 for assembly in one of the embodiments of Figs. 3 and 4.
DETAILED DESCRTPTION OF THE PREFERRED EMBODIMENTS
Fig. 1 illustrates a binary resonant grating structure l0 having a substrate 11 of light t:ransmissive material of refractive index, n2, a plurality of parallel grooves 12, and inserts 13 for the grooves provided by a second light transmissive material of refractive index nl. In this context, "light" means not only signals in the ;spectrum of visible light, but also signals in the full spectrum, of frequencies typically handled by optical transmission systerns of the known prior art.
The binary grating structure 10 provides a zeroth order WO 01/27666 PCTlUS00/25345 diffraction grating (no higher order diffracted fields). Light signals are either passed or reflected. The index of refraction of the resulting filter 10 can be represented by an effective uniform homogeneous material havin<~ an effective index of refraction (neff) In the case where a grating strucaure is viewed from either an input region 14 or an output region 15 having a refractive index, no, and the diffraction index within the grating region satisfies the index criteria of no< neff >nz~ a surface propagating field will be produced which is trapped within the grating region due to total internal reflection (effective waveguide).
Fig. lA illustrates that a zeroth order grating region defined by nl and n2 has an effective index, neff, which is higher than the surrounding homogeneous regions, thus giving it the appearance of a planar (effective) waveguide. If a diffracted field is coupled into the mode of this effective waveguide, the field will resonate and reflect all of the light energy backwards. This.resonance effect results in a total reflection of the incident field from the surface, and it is extremely sensitive to wavelength to provide a narrow-band reflection filter. All other frequencies pass through the filter.
Fig. 2 shows another embodiment o:E a single resonant grating filter 16 in which the substrate 17 of refractive index nz has a sinusoidal shape and may have a dielectric coating 18 of refractive index, n~, The effective index of refraction for the filter, neff, is again greater than the index of the substrate or the coating as illustrated in the graph of refraction index in Fig. 2A. The one dimensional grating parameters are as follows:
substrate index of refraction = 1.52, grating period = 594.95nm, modulation depth of grating = 450nm, coating index of refraction - 1.58, coating thickness = 600nm.
The present invention utilizes a plurality of resonant grating filters (such as elements l0a-:LOe in Fig. 3, for example) for multiplexing and demultiplexing optical signals (WDM system) .
Multiplexing is the conversion of multiple signals in parallel to signals transmitted through a single channel. Demultiplexing distributes signals from a single channel to multiple channels operating in parallel. There are a number of architectural configurations for constructing a WDM system with resonant grating filters according to the present invention.
Referring to Fig. 3, a device :?0 includes a plurality of zeroth order resonant grating filters l0a-10e of the type described for Fig. 1, which are assembled in a stacked array with each filter l0a-l0e at an angle of forty-five degrees between a horizontal reference and a vertical reference. The resonant filters l0a-10e can be embedded in material 21 having an index of refraction, nb, which matches the index of the substrate material (n~) of the resonant filter (i.e., na - nb) . The material 21 can be a liquid, such as a light transmissive oil, or it can be a solid such as a light transmissive plastic material. If adhesive is used to assemble the solid material with the filters l0a-IOe, a light transmissive material, such an epoxy, is used. The filters l0a-l0e c:an also be mounted between top and bottom supporting structures (not shown) each having a sawtooth edge with angled surfaces for orienting the filters l0a-l0e at the selected angle. The resulting assembly 20 can take a prism block form as seen in Fig. 3, or could take on other forms as well.
The effective index (n~ff) of the zeroth order grating region is also very close to the substrate index. Therefore, since the index of refraction is same for both the input and output regions surrounding each resonant structure, the Fresnel reflections and therefore the cross-talk between channels is minimized.
A modified form of Fig. 3 can be constructed using the sawtooth mounting members (top and bottom) and using a plurality of sinusoidal gratings of the type seen in Fig. 2, having their axes oriented at about forty-five degrees . Spacer material could be used in the form of liquid or solid material.
In Fig. 3, the incident signal impinges on the filters l0a l0e at an identical angle 8, to prozride reflected wavelengths Al.?~2.l~s.l~a . . - 1~". respectively, in a demultiplexing mode. The light transmissive spacer material 21 assembled in spaces between the resonant grating filters, has a refractive index such that the incident signal received by a second one of said resonant grating filters 10b is different i:rom the incident signal received by a first one of said resonant grating filters 10a.
This shift in frequency and wavelength occurs for filters lOc-l0e as well. This results in differing wavelengths 1~1,?~2,~3,~9 . . . h".
The bidirectional arrows in Fig. 3 represents that the signals of wavelengths 1~1,1~2,A3.?~4 ... 1~" can also be transmitted along separate channels, and be reflected back along a common axis of propagation in the multiplexing mode.
Fig. 4 shows a second embodiment of plurality of spaced nearly parallel filters lOf-lOj, where each filter 10f-lOj is identical and is shifted to a respective, slightly varying one of angles, 61, 82, 83, 89, . . 6~ around forty-five degrees to provide reflected wavelengths J~1,1~2,1~3, A9 . . . 1~~, respectively, in a demultiplexing mode. The bidireca Tonal arrows in Fig. 4 represents that the signals of wavelengths A1, A2. X3,1,,4 . . . 1~n can also be transmitted along separate channels, and be reflected back along a common axis of propagation in the multiplexing mode.
Figs. 5A and 5B illustrates the performance of a 16-channel WDM system based on Fig. 3 or Fig. 4, each of which provides a single resonant filter set. Reflectance of 100 occurs around certain center frequencies as seen in Fig. 5a. The drop off in response to sideband frequencies is shown in the decibel plot of Fig. SB. There is some crosstalk between -5dB and -lOdB.
Fig. 6 shows a triple reflection filter embodiment, in which each channel has its signal reflected through three sub filters, such as sub-filters 31a-31c for A1. Each set of three filters 32a-32c, 33a-33c, 34a-34c and 35a-35c corresponds to channels for 1~2,A3,1~9 ... An. These signals are multiplexed and demultiplexed to a single channel 30. The triple resonant filter set provides for each channel to reflect off three identical filters, thus reducing the side-bands.
The embodiment in Fig. 6 reduces channel cross-talk.
Figs. 7A and 7B illustrate the perfornnance of a triple resonant filter set based on the same filter design above. The channel reflectance is still 100 around the tuned channel frequencies, but note the reduction in channel cro:as-talk to the -20dB region in Fig. 7B. Channel separation is 0.8nm, allowing 16 channels in 14.4nm and twice to three times that many total possible channels in a fiber optic system. The total available bandwidth is about 50nm around a wavelength of 1550nm.
There are many advantages of the ;present invention. Because each resonant structure is embedded within an index-matched region, both the input and output regions of the resonant filter have the same material characteristics. Therefore, an incident field will experience minimal or no Fresnel reflections away from the resonance peak, to limit sideband reflections.
Resonant structures can be placed at a particular angle with respect to the incident field to redirect the resonant energy to another portion of the planar wavegui.de.
Resonant filters do not have any inherent optical losses giving then a 100% throughput at the resonance center wavelength.
The systems of the present invention systems can be designed to be either sensitive or insensitive to the incident fields polarization.
A one dimensionally structured resonant filter exhibits polarization properties, while a symmetric two dimensionally structured resonant filter operates with unpolarized light.
Resonant grating filters can be designed using several different architectures, including binary structures and continuous surface relief structures. A structure such as illustrated in Fig. 1 is polarization sensitive, because it is considered a one dimensional grating structure (groove: running in parallel in one direction). In order to construct a resonant filter that is not polarization-sensitive, a symmetrical two-dimensional architec ture can be used.
Figs. 8A,.8B and 8C show a method of producing a master using thin film techniques, and then using the master to make a plurality of the sinusoidal type filters of the type shown in Fig. 2 above. There a number of fabrication technologies available such as direct-write, e-beam lithography; direct-write, focused-ion beam lithography; interfe~:ometry and gray-scale mask lithography. Fig. 8A illustrates an. interferometry method in _g_ which two beams are focused on a sub:~trate 30 having a layer of photoresist material 31 deposited thereon. When the beams interfere they produce a wave pattern of intensity that develops the photoresist in proportion to the intensity or amplitude in a specific region. If the intensity is low due to low reinforcement, the photoresist is cured less. The result is a layer of photoresist developed in a sinusoidal or grated pattern as seen in Fig. 8B. Next, if a beam is applied to etch the substrate, its effects will be tempered by thicker portions of photoresist, but affected less by thinner layers of photoresist.
Consequently, the sinusoidal pattern is transferred to the substrate, which becomes a master f:or making a plurality of filters having a sinusoidal grating surface. Filter substrates can be made from the master using techniques, such as plating, coating, pressing, casting, injection molding. The materials for the sinusoidal filter bodies may include plastics, epoxies, glasses and metals.
A coating can be applied to these filter bodies using thin film coating with a material having a relatively higher index of refraction than the substrate, or by ion implantation in the surface to create a region of higher refractive index.
This has been a description of the preferred embodiments of the method and apparatus of the present invention. Those of ordinary skill in this art will recognize that modifications might be made while still coming within the spirit and scope of the invention and, therefore, to define the embodiments of the invention, the following claims are made.
_g_
Fig. 1 is a perspective diagram of a first embodiment of an individual resonant grating filter of the prior art;
Fig. lA is refraction index diagram for the embodiment of Fig. l;
Fig. 2 is a perspective diagram of ~ second embodiment of an individual resonant grating filter of the prior art;
Fig. 2A is refraction index diagram for the embodiment of Fig. 2;
Fig. 3 is a first embodiment of a multiplexing/
demultiplexing device of the present invention incorporating a plurality of the filters seen in Fig. 1;
Fig. 4 is a second embodiment of a multiplexing/
demultiplexing device of the present invention;
Fig. 5A and Fig. 5B are reflectance vs. wavel.ength diagrams for the embodiment of Fig. 4.
Fig. 6 is a third embodiment of a multiplexing/
demultiplexing device of the present :invention;
Fig. 7A and Fig. 7B are reflectance vs. wavelength diagrams for the embodiment of Fig. 6; and Figs. 8A, 8B and 8C illustrate a method of making a plurality of the filters of the type in Fig. 2 for assembly in one of the embodiments of Figs. 3 and 4.
DETAILED DESCRTPTION OF THE PREFERRED EMBODIMENTS
Fig. 1 illustrates a binary resonant grating structure l0 having a substrate 11 of light t:ransmissive material of refractive index, n2, a plurality of parallel grooves 12, and inserts 13 for the grooves provided by a second light transmissive material of refractive index nl. In this context, "light" means not only signals in the ;spectrum of visible light, but also signals in the full spectrum, of frequencies typically handled by optical transmission systerns of the known prior art.
The binary grating structure 10 provides a zeroth order WO 01/27666 PCTlUS00/25345 diffraction grating (no higher order diffracted fields). Light signals are either passed or reflected. The index of refraction of the resulting filter 10 can be represented by an effective uniform homogeneous material havin<~ an effective index of refraction (neff) In the case where a grating strucaure is viewed from either an input region 14 or an output region 15 having a refractive index, no, and the diffraction index within the grating region satisfies the index criteria of no< neff >nz~ a surface propagating field will be produced which is trapped within the grating region due to total internal reflection (effective waveguide).
Fig. lA illustrates that a zeroth order grating region defined by nl and n2 has an effective index, neff, which is higher than the surrounding homogeneous regions, thus giving it the appearance of a planar (effective) waveguide. If a diffracted field is coupled into the mode of this effective waveguide, the field will resonate and reflect all of the light energy backwards. This.resonance effect results in a total reflection of the incident field from the surface, and it is extremely sensitive to wavelength to provide a narrow-band reflection filter. All other frequencies pass through the filter.
Fig. 2 shows another embodiment o:E a single resonant grating filter 16 in which the substrate 17 of refractive index nz has a sinusoidal shape and may have a dielectric coating 18 of refractive index, n~, The effective index of refraction for the filter, neff, is again greater than the index of the substrate or the coating as illustrated in the graph of refraction index in Fig. 2A. The one dimensional grating parameters are as follows:
substrate index of refraction = 1.52, grating period = 594.95nm, modulation depth of grating = 450nm, coating index of refraction - 1.58, coating thickness = 600nm.
The present invention utilizes a plurality of resonant grating filters (such as elements l0a-:LOe in Fig. 3, for example) for multiplexing and demultiplexing optical signals (WDM system) .
Multiplexing is the conversion of multiple signals in parallel to signals transmitted through a single channel. Demultiplexing distributes signals from a single channel to multiple channels operating in parallel. There are a number of architectural configurations for constructing a WDM system with resonant grating filters according to the present invention.
Referring to Fig. 3, a device :?0 includes a plurality of zeroth order resonant grating filters l0a-10e of the type described for Fig. 1, which are assembled in a stacked array with each filter l0a-l0e at an angle of forty-five degrees between a horizontal reference and a vertical reference. The resonant filters l0a-10e can be embedded in material 21 having an index of refraction, nb, which matches the index of the substrate material (n~) of the resonant filter (i.e., na - nb) . The material 21 can be a liquid, such as a light transmissive oil, or it can be a solid such as a light transmissive plastic material. If adhesive is used to assemble the solid material with the filters l0a-IOe, a light transmissive material, such an epoxy, is used. The filters l0a-l0e c:an also be mounted between top and bottom supporting structures (not shown) each having a sawtooth edge with angled surfaces for orienting the filters l0a-l0e at the selected angle. The resulting assembly 20 can take a prism block form as seen in Fig. 3, or could take on other forms as well.
The effective index (n~ff) of the zeroth order grating region is also very close to the substrate index. Therefore, since the index of refraction is same for both the input and output regions surrounding each resonant structure, the Fresnel reflections and therefore the cross-talk between channels is minimized.
A modified form of Fig. 3 can be constructed using the sawtooth mounting members (top and bottom) and using a plurality of sinusoidal gratings of the type seen in Fig. 2, having their axes oriented at about forty-five degrees . Spacer material could be used in the form of liquid or solid material.
In Fig. 3, the incident signal impinges on the filters l0a l0e at an identical angle 8, to prozride reflected wavelengths Al.?~2.l~s.l~a . . - 1~". respectively, in a demultiplexing mode. The light transmissive spacer material 21 assembled in spaces between the resonant grating filters, has a refractive index such that the incident signal received by a second one of said resonant grating filters 10b is different i:rom the incident signal received by a first one of said resonant grating filters 10a.
This shift in frequency and wavelength occurs for filters lOc-l0e as well. This results in differing wavelengths 1~1,?~2,~3,~9 . . . h".
The bidirectional arrows in Fig. 3 represents that the signals of wavelengths 1~1,1~2,A3.?~4 ... 1~" can also be transmitted along separate channels, and be reflected back along a common axis of propagation in the multiplexing mode.
Fig. 4 shows a second embodiment of plurality of spaced nearly parallel filters lOf-lOj, where each filter 10f-lOj is identical and is shifted to a respective, slightly varying one of angles, 61, 82, 83, 89, . . 6~ around forty-five degrees to provide reflected wavelengths J~1,1~2,1~3, A9 . . . 1~~, respectively, in a demultiplexing mode. The bidireca Tonal arrows in Fig. 4 represents that the signals of wavelengths A1, A2. X3,1,,4 . . . 1~n can also be transmitted along separate channels, and be reflected back along a common axis of propagation in the multiplexing mode.
Figs. 5A and 5B illustrates the performance of a 16-channel WDM system based on Fig. 3 or Fig. 4, each of which provides a single resonant filter set. Reflectance of 100 occurs around certain center frequencies as seen in Fig. 5a. The drop off in response to sideband frequencies is shown in the decibel plot of Fig. SB. There is some crosstalk between -5dB and -lOdB.
Fig. 6 shows a triple reflection filter embodiment, in which each channel has its signal reflected through three sub filters, such as sub-filters 31a-31c for A1. Each set of three filters 32a-32c, 33a-33c, 34a-34c and 35a-35c corresponds to channels for 1~2,A3,1~9 ... An. These signals are multiplexed and demultiplexed to a single channel 30. The triple resonant filter set provides for each channel to reflect off three identical filters, thus reducing the side-bands.
The embodiment in Fig. 6 reduces channel cross-talk.
Figs. 7A and 7B illustrate the perfornnance of a triple resonant filter set based on the same filter design above. The channel reflectance is still 100 around the tuned channel frequencies, but note the reduction in channel cro:as-talk to the -20dB region in Fig. 7B. Channel separation is 0.8nm, allowing 16 channels in 14.4nm and twice to three times that many total possible channels in a fiber optic system. The total available bandwidth is about 50nm around a wavelength of 1550nm.
There are many advantages of the ;present invention. Because each resonant structure is embedded within an index-matched region, both the input and output regions of the resonant filter have the same material characteristics. Therefore, an incident field will experience minimal or no Fresnel reflections away from the resonance peak, to limit sideband reflections.
Resonant structures can be placed at a particular angle with respect to the incident field to redirect the resonant energy to another portion of the planar wavegui.de.
Resonant filters do not have any inherent optical losses giving then a 100% throughput at the resonance center wavelength.
The systems of the present invention systems can be designed to be either sensitive or insensitive to the incident fields polarization.
A one dimensionally structured resonant filter exhibits polarization properties, while a symmetric two dimensionally structured resonant filter operates with unpolarized light.
Resonant grating filters can be designed using several different architectures, including binary structures and continuous surface relief structures. A structure such as illustrated in Fig. 1 is polarization sensitive, because it is considered a one dimensional grating structure (groove: running in parallel in one direction). In order to construct a resonant filter that is not polarization-sensitive, a symmetrical two-dimensional architec ture can be used.
Figs. 8A,.8B and 8C show a method of producing a master using thin film techniques, and then using the master to make a plurality of the sinusoidal type filters of the type shown in Fig. 2 above. There a number of fabrication technologies available such as direct-write, e-beam lithography; direct-write, focused-ion beam lithography; interfe~:ometry and gray-scale mask lithography. Fig. 8A illustrates an. interferometry method in _g_ which two beams are focused on a sub:~trate 30 having a layer of photoresist material 31 deposited thereon. When the beams interfere they produce a wave pattern of intensity that develops the photoresist in proportion to the intensity or amplitude in a specific region. If the intensity is low due to low reinforcement, the photoresist is cured less. The result is a layer of photoresist developed in a sinusoidal or grated pattern as seen in Fig. 8B. Next, if a beam is applied to etch the substrate, its effects will be tempered by thicker portions of photoresist, but affected less by thinner layers of photoresist.
Consequently, the sinusoidal pattern is transferred to the substrate, which becomes a master f:or making a plurality of filters having a sinusoidal grating surface. Filter substrates can be made from the master using techniques, such as plating, coating, pressing, casting, injection molding. The materials for the sinusoidal filter bodies may include plastics, epoxies, glasses and metals.
A coating can be applied to these filter bodies using thin film coating with a material having a relatively higher index of refraction than the substrate, or by ion implantation in the surface to create a region of higher refractive index.
This has been a description of the preferred embodiments of the method and apparatus of the present invention. Those of ordinary skill in this art will recognize that modifications might be made while still coming within the spirit and scope of the invention and, therefore, to define the embodiments of the invention, the following claims are made.
_g_
Claims (19)
1. An optical device for operation as either a multiplexer or demultiplexer, the device comprising:
a plurality of resonant grating filters arranged along a propagation axis that extends to a multiplexed optical channel for a plurality of optical signal frequencies;
wherein said filters reflect optical signals at respective resonant frequencies, and wherein said filters transmit optical signals at frequencies other than their respective resonant frequencies along the propagation axis; and wherein each of said filters is arranged at a non-perpendicular angle to the propagation axis to reflect a respective optical signal between the propagation axis and a respective one of a plurality of discrete frequency channels, which are provided for carrying optical signals having respective discrete frequencies.
a plurality of resonant grating filters arranged along a propagation axis that extends to a multiplexed optical channel for a plurality of optical signal frequencies;
wherein said filters reflect optical signals at respective resonant frequencies, and wherein said filters transmit optical signals at frequencies other than their respective resonant frequencies along the propagation axis; and wherein each of said filters is arranged at a non-perpendicular angle to the propagation axis to reflect a respective optical signal between the propagation axis and a respective one of a plurality of discrete frequency channels, which are provided for carrying optical signals having respective discrete frequencies.
2. The optical device of claim 1, wherein the resonant grating filters are binary resonant filter grating structures.
3. The optical device of claim 3, wherein the resonant grating filters have a substrate with a sinusoidal surface.
4. The optical device of claim 3, wherein the sinusoidal surface is coated with dielectric coating.
5. The optical device of claim 1, further comprising light transmissive spacer material assembled in spaces between the resonant grating filters, said light transmissive spacing material having a refractive index such that an incident signal received by a second one of said resonant grating filter is different from an incident signal received by a first one of said resonant grating filters.
6. The optical device of claim 5, wherein the resonant grating filters are binary resonant filter grating structures.
7. The optical device of claim 6, wherein the light transmissive spacer material is a solid.
8. The optical device of claim 6, wherein the light transmissive spacer material is a liquid.
9. The optical device of claim 5, wherein the resonant grating filters have a substrate with a sinusoidal surface.
10. The optical device of claim 9, wherein the sinusoidal surface is coated with dielectric coating.
11. The optical device of claim 1, said resonant grating filters are spaced apart by air spaces, and wherein each of said resonant grating filters is disposed at a slightly different angle to the propagation axis than a preceding one of said resonant grating filters to reflect a signal which differs in frequency from a reflected signal for a preceding one of said resonant grating filters.
12. The optical device of claim 11, wherein the resonant grating filters have structures which are identical.
13. The optical device of claim 11, further comprising at least one additional resonant grating filter in each channel to reflect each resonant frequency signal at one additional time.
14. The optical device of claim 11, further comprising at least two additional resonant grating filters in each channel to reflect each resonant frequency at least two additional times.
15. The optical device of claim 11, wherein the resonant grating filters are binary resonant filter grating structures.
16. The optical device of claim 11, wherein the resonant grating filters have a substrate with a sinusoidal surface.
17. The optical device of claim 14, wherein the sinusoidal surface is coated with dielectric coating.
18. The optical device of claim 1, wherein the resonant grating filters are zeroth order grating filters.
19. The optical device of claim 1, wherein the resonant grating filters have structures which are identical.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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US09/398,242 US6212312B1 (en) | 1999-09-17 | 1999-09-17 | Optical multiplexer/demultiplexer using resonant grating filters |
US09/398,242 | 1999-09-17 | ||
PCT/US2000/025345 WO2001027666A2 (en) | 1999-09-17 | 2000-09-15 | Optical multiplexer/demultiplexer using resonant grating filters |
Publications (1)
Publication Number | Publication Date |
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CA2351535A1 true CA2351535A1 (en) | 2001-04-19 |
Family
ID=23574588
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Application Number | Title | Priority Date | Filing Date |
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CA002351535A Abandoned CA2351535A1 (en) | 1999-09-17 | 2000-09-15 | Optical multiplexer/demultiplexer using resonant grating filters |
Country Status (8)
Country | Link |
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US (1) | US6212312B1 (en) |
EP (1) | EP1145052A2 (en) |
JP (1) | JP2003514250A (en) |
KR (1) | KR20010099801A (en) |
AU (1) | AU3261301A (en) |
BR (1) | BR0007159A (en) |
CA (1) | CA2351535A1 (en) |
WO (1) | WO2001027666A2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107065076A (en) * | 2017-06-28 | 2017-08-18 | 北极光电(深圳)有限公司 | A kind of OWDM integrated device of microstructure and preparation method thereof |
Families Citing this family (84)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8466795B2 (en) | 1997-01-21 | 2013-06-18 | Pragmatus Mobile LLC | Personal security and tracking system |
US7167615B1 (en) * | 1999-11-05 | 2007-01-23 | Board Of Regents, The University Of Texas System | Resonant waveguide-grating filters and sensors and methods for making and using same |
US8111401B2 (en) * | 1999-11-05 | 2012-02-07 | Robert Magnusson | Guided-mode resonance sensors employing angular, spectral, modal, and polarization diversity for high-precision sensing in compact formats |
JP2001141924A (en) * | 1999-11-16 | 2001-05-25 | Matsushita Electric Ind Co Ltd | Branching device and branching light-receiving element |
US6332050B1 (en) * | 2000-04-05 | 2001-12-18 | Board Of Supervisors Of Louisiana State University And Agricultural And Mechanical College | Optical slab waveguide for massive, high-speed interconnects |
US6858834B2 (en) * | 2000-10-18 | 2005-02-22 | Fibera, Inc. | Light wavelength meter |
US6795459B2 (en) | 2000-10-18 | 2004-09-21 | Fibera, Inc. | Light frequency locker |
US6905900B1 (en) * | 2000-11-28 | 2005-06-14 | Finisar Corporation | Versatile method and system for single mode VCSELs |
US7065124B2 (en) * | 2000-11-28 | 2006-06-20 | Finlsar Corporation | Electron affinity engineered VCSELs |
US6990135B2 (en) * | 2002-10-28 | 2006-01-24 | Finisar Corporation | Distributed bragg reflector for optoelectronic device |
US6836501B2 (en) * | 2000-12-29 | 2004-12-28 | Finisar Corporation | Resonant reflector for increased wavelength and polarization control |
TWI227799B (en) * | 2000-12-29 | 2005-02-11 | Honeywell Int Inc | Resonant reflector for increased wavelength and polarization control |
US6839517B2 (en) | 2001-02-12 | 2005-01-04 | Agere Systems Inc. | Apparatus and method for transmitting optical signals through a single fiber optical network |
US6636654B2 (en) * | 2001-03-30 | 2003-10-21 | Optical Research Associates | Programmable optical switching add/drop multiplexer |
US6751373B2 (en) | 2001-04-10 | 2004-06-15 | Gazillion Bits, Inc. | Wavelength division multiplexing with narrow band reflective filters |
US6904200B2 (en) * | 2001-09-14 | 2005-06-07 | Fibera, Inc. | Multidimensional optical gratings |
US6807339B1 (en) * | 2001-09-14 | 2004-10-19 | Fibera, Inc. | Wavelength division multiplexing and de-multiplexing system |
US6718092B2 (en) * | 2001-09-14 | 2004-04-06 | Fibera, Inc. | Frequency detection, tuning and stabilization system |
US6571033B2 (en) | 2001-09-28 | 2003-05-27 | Corning Incorporated | Optical signal device |
US7203421B2 (en) * | 2001-09-28 | 2007-04-10 | Optical Research Associates | Littrow grating based OADM |
US6804060B1 (en) | 2001-09-28 | 2004-10-12 | Fibera, Inc. | Interference filter fabrication |
WO2003042720A2 (en) * | 2001-11-09 | 2003-05-22 | Fibera, Inc. | Multidimensional optical grating fabrication and application |
JP3687848B2 (en) * | 2001-11-28 | 2005-08-24 | 日立金属株式会社 | Thin film filter for optical multiplexer / demultiplexer and method for manufacturing the same |
CN100340076C (en) * | 2001-11-30 | 2007-09-26 | 台达电子工业股份有限公司 | High-density wavelength division multiplexer |
US20030175006A1 (en) * | 2002-03-15 | 2003-09-18 | Wildeman George F. | Optical filter array and method of use |
AU2003230630A1 (en) * | 2002-03-15 | 2003-09-29 | Corning Incorporated | Optical filter array and method of use |
US7268927B2 (en) * | 2002-03-15 | 2007-09-11 | Corning Incorporated | Tunable optical filter array and method of use |
US6912073B2 (en) * | 2002-03-15 | 2005-06-28 | Corning Incorporated | Optical filter array and method of use |
US20030174424A1 (en) * | 2002-03-15 | 2003-09-18 | Hart Brian T. | Monolithic filter array |
WO2003107045A2 (en) * | 2002-06-12 | 2003-12-24 | Optical Research Associates | Wavelength selective optical switch |
WO2004010175A2 (en) * | 2002-07-23 | 2004-01-29 | Optical Research Associates | East-west separable, reconfigurable optical add/drop multiplexer |
JP2004054181A (en) * | 2002-07-24 | 2004-02-19 | Fujitsu Media Device Kk | Wavelength filter, variable wavelength filter, and optical element |
KR100514385B1 (en) * | 2002-12-03 | 2005-09-13 | 최준국 | Optical add/drop device and bus-type WDM PON system using this |
US6965626B2 (en) * | 2002-09-03 | 2005-11-15 | Finisar Corporation | Single mode VCSEL |
US6813293B2 (en) * | 2002-11-21 | 2004-11-02 | Finisar Corporation | Long wavelength VCSEL with tunnel junction, and implant |
US20040222363A1 (en) * | 2003-05-07 | 2004-11-11 | Honeywell International Inc. | Connectorized optical component misalignment detection system |
US20040247250A1 (en) * | 2003-06-03 | 2004-12-09 | Honeywell International Inc. | Integrated sleeve pluggable package |
US7075962B2 (en) * | 2003-06-27 | 2006-07-11 | Finisar Corporation | VCSEL having thermal management |
US7277461B2 (en) * | 2003-06-27 | 2007-10-02 | Finisar Corporation | Dielectric VCSEL gain guide |
US7149383B2 (en) * | 2003-06-30 | 2006-12-12 | Finisar Corporation | Optical system with reduced back reflection |
US6961489B2 (en) * | 2003-06-30 | 2005-11-01 | Finisar Corporation | High speed optical system |
US20060056762A1 (en) * | 2003-07-02 | 2006-03-16 | Honeywell International Inc. | Lens optical coupler |
US7210857B2 (en) * | 2003-07-16 | 2007-05-01 | Finisar Corporation | Optical coupling system |
US20050013542A1 (en) * | 2003-07-16 | 2005-01-20 | Honeywell International Inc. | Coupler having reduction of reflections to light source |
US20050013539A1 (en) * | 2003-07-17 | 2005-01-20 | Honeywell International Inc. | Optical coupling system |
US6887801B2 (en) * | 2003-07-18 | 2005-05-03 | Finisar Corporation | Edge bead control method and apparatus |
US7415210B2 (en) * | 2003-07-28 | 2008-08-19 | Allied Telesis, Inc. | Bidirectional optical signal multiplexer/demultiplexer |
US7031363B2 (en) * | 2003-10-29 | 2006-04-18 | Finisar Corporation | Long wavelength VCSEL device processing |
US7058257B2 (en) * | 2003-12-30 | 2006-06-06 | Lightwaves 2020, Inc. | Miniature WDM add/drop multiplexer and method of manufacture thereof |
US7829912B2 (en) * | 2006-07-31 | 2010-11-09 | Finisar Corporation | Efficient carrier injection in a semiconductor device |
US7596165B2 (en) * | 2004-08-31 | 2009-09-29 | Finisar Corporation | Distributed Bragg Reflector for optoelectronic device |
US7920612B2 (en) * | 2004-08-31 | 2011-04-05 | Finisar Corporation | Light emitting semiconductor device having an electrical confinement barrier near the active region |
JP4139420B2 (en) * | 2005-03-25 | 2008-08-27 | ナルックス株式会社 | Wavelength filter |
JP2006349776A (en) * | 2005-06-13 | 2006-12-28 | Sharp Corp | Wavelength selection element |
JP4520402B2 (en) * | 2005-12-07 | 2010-08-04 | 株式会社リコー | Multi-wavelength light switching element, multi-wavelength light switching device, color light switching element, color light switching device, multi-wavelength light switching element array, color light switching element array, multi-color image display device and color image display device |
EP1862827B2 (en) | 2006-05-31 | 2012-05-30 | CSEM Centre Suisse d'Electronique et de Microtechnique SA - Recherche et Développement | Nano-structured Zero-order diffractive filter |
JP4633005B2 (en) * | 2006-06-13 | 2011-02-16 | 株式会社リコー | Optical switching unit, optical switching unit array and image display device |
KR100927590B1 (en) * | 2006-12-05 | 2009-11-23 | 한국전자통신연구원 | Resonant Reflective Light Filter and Biosensor Using the Same |
KR100899811B1 (en) * | 2006-12-05 | 2009-05-27 | 한국전자통신연구원 | Guided mode resonance filter including high refractive index organic material and optical biosensor having the same |
JP5293969B2 (en) * | 2007-03-30 | 2013-09-18 | 綜研化学株式会社 | Wavelength demultiplexing optical element |
US8031752B1 (en) | 2007-04-16 | 2011-10-04 | Finisar Corporation | VCSEL optimized for high speed data |
JP5443701B2 (en) * | 2008-04-03 | 2014-03-19 | パナソニック株式会社 | Gas concentration measuring device |
JP5256906B2 (en) * | 2008-07-28 | 2013-08-07 | 株式会社リコー | Wavelength selection filter, filter device, light source device, optical device, and refractive index sensor |
US8863240B2 (en) * | 2010-10-20 | 2014-10-14 | T-Mobile Usa, Inc. | Method and system for smart card migration |
WO2013065035A1 (en) | 2011-11-03 | 2013-05-10 | Verifood Ltd. | Low-cost spectrometry system for end-user food analysis |
US9417394B2 (en) * | 2012-08-08 | 2016-08-16 | The Board Of Regents Of The University Of Texas System | Spectrally dense comb-like filters fashioned with thick-guided-mode resonant gratings |
WO2014172195A2 (en) * | 2013-04-16 | 2014-10-23 | Materion Corporation | Filter array with reduced stray light |
GB2543655B (en) | 2013-08-02 | 2017-11-01 | Verifood Ltd | Compact spectrometer comprising a diffuser, filter matrix, lens array and multiple sensor detector |
US9614636B2 (en) | 2013-08-23 | 2017-04-04 | Sumitomo Electric Industries, Ltd. | Receiver optical module for wavelength multiplexed signal |
EP3090239A4 (en) | 2014-01-03 | 2018-01-10 | Verifood Ltd. | Spectrometry systems, methods, and applications |
US9945666B2 (en) | 2014-01-08 | 2018-04-17 | The Regents Of The University Of Michigan | Narrowband transmission filter |
EP3209983A4 (en) | 2014-10-23 | 2018-06-27 | Verifood Ltd. | Accessories for handheld spectrometer |
WO2016125164A2 (en) | 2015-02-05 | 2016-08-11 | Verifood, Ltd. | Spectrometry system applications |
WO2016125165A2 (en) | 2015-02-05 | 2016-08-11 | Verifood, Ltd. | Spectrometry system with visible aiming beam |
US10066990B2 (en) | 2015-07-09 | 2018-09-04 | Verifood, Ltd. | Spatially variable filter systems and methods |
WO2017044909A1 (en) | 2015-09-11 | 2017-03-16 | L-3 Communications Cincinnati Electronics Corporation | Hyperspectral optical element for monolithic detectors |
US9709746B2 (en) * | 2015-11-17 | 2017-07-18 | International Business Machines Corporation | Micro-filter structures for wavelength division multiplexing in polymer waveguides |
US10203246B2 (en) | 2015-11-20 | 2019-02-12 | Verifood, Ltd. | Systems and methods for calibration of a handheld spectrometer |
EP3488204A4 (en) | 2016-07-20 | 2020-07-22 | Verifood Ltd. | Accessories for handheld spectrometer |
US10791933B2 (en) | 2016-07-27 | 2020-10-06 | Verifood, Ltd. | Spectrometry systems, methods, and applications |
US10571703B2 (en) * | 2017-12-11 | 2020-02-25 | North Inc. | Wavelength combiner method using photonic integrated circuit with respective input facets for corresponding lasers |
US10788633B2 (en) * | 2018-04-30 | 2020-09-29 | Hewlett Packard Enterprise Development Lp | Complementary reverse order filters |
CN108957612A (en) * | 2018-07-26 | 2018-12-07 | 北极光电(深圳)有限公司 | A kind of film filter component and preparation method thereof |
RU185920U1 (en) * | 2018-08-13 | 2018-12-24 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Санкт-Петербургский государственный университет" (СПбГУ) | NARROW SPECTRAL OPTICAL FILTER |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3806804A (en) * | 1965-06-11 | 1974-04-23 | Martin Marietta Corp | Radio telephone system having automatic channel selection |
US4111524A (en) | 1977-04-14 | 1978-09-05 | Bell Telephone Laboratories, Incorporated | Wavelength division multiplexer |
US4474424A (en) | 1981-03-20 | 1984-10-02 | At&T Bell Laboratories | Optical multi/demultiplexer using interference filters |
US5216680A (en) | 1991-07-11 | 1993-06-01 | Board Of Regents, The University Of Texas System | Optical guided-mode resonance filter |
US5194848A (en) * | 1991-09-09 | 1993-03-16 | Hitek-Protek Systems Inc. | Intrusion detection apparatus having multiple channel signal processing |
GB9213459D0 (en) * | 1992-06-24 | 1992-08-05 | British Telecomm | Characterisation of communications systems using a speech-like test stimulus |
JP3284659B2 (en) * | 1993-04-09 | 2002-05-20 | 株式会社フジクラ | Optical switching device for WDM optical communication |
US5457760A (en) | 1994-05-06 | 1995-10-10 | At&T Ipm Corp. | Wavelength division optical multiplexing elements |
US5602959A (en) * | 1994-12-05 | 1997-02-11 | Motorola, Inc. | Method and apparatus for characterization and reconstruction of speech excitation waveforms |
NL9500004A (en) | 1995-01-02 | 1996-08-01 | Nederland Ptt | Integrated optical wavelength demultiplexer. |
US5583683A (en) | 1995-06-15 | 1996-12-10 | Optical Corporation Of America | Optical multiplexing device |
US5696615A (en) | 1995-11-13 | 1997-12-09 | Ciena Corporation | Wavelength division multiplexed optical communication systems employing uniform gain optical amplifiers |
US6035089A (en) * | 1997-06-11 | 2000-03-07 | Lockheed Martin Energy Research Corporation | Integrated narrowband optical filter based on embedded subwavelength resonant grating structures |
-
1999
- 1999-09-17 US US09/398,242 patent/US6212312B1/en not_active Expired - Fee Related
-
2000
- 2000-09-15 EP EP00991375A patent/EP1145052A2/en not_active Withdrawn
- 2000-09-15 CA CA002351535A patent/CA2351535A1/en not_active Abandoned
- 2000-09-15 KR KR1020017006229A patent/KR20010099801A/en not_active Application Discontinuation
- 2000-09-15 BR BR0007159-5A patent/BR0007159A/en not_active Application Discontinuation
- 2000-09-15 WO PCT/US2000/025345 patent/WO2001027666A2/en not_active Application Discontinuation
- 2000-09-15 JP JP2001530621A patent/JP2003514250A/en active Pending
- 2000-09-15 AU AU32613/01A patent/AU3261301A/en not_active Abandoned
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107065076A (en) * | 2017-06-28 | 2017-08-18 | 北极光电(深圳)有限公司 | A kind of OWDM integrated device of microstructure and preparation method thereof |
Also Published As
Publication number | Publication date |
---|---|
WO2001027666A2 (en) | 2001-04-19 |
BR0007159A (en) | 2001-07-31 |
WO2001027666A3 (en) | 2002-09-26 |
EP1145052A2 (en) | 2001-10-17 |
US6212312B1 (en) | 2001-04-03 |
AU3261301A (en) | 2001-04-23 |
KR20010099801A (en) | 2001-11-09 |
JP2003514250A (en) | 2003-04-15 |
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