Some of the key optical components of lithography lasers are very sensitive to intensive UV radiation. Intensive UV radiation can cause color center formation in these components. The color centers are reason for laser energy dropping, worse laser-bandwidth and limited life-time. The on-line monitoring...http://www.google.ca/patents/US6839375?utm_source=gb-gplus-sharePatent US6839375 - On-line quality control of the key optical components in lithography lasers using laser induced fluorescence
