Abstract
It is well known that hydrogen loading1 drastically enhances the photosensitivity of germanosilicate glass. Hydrogen loading has made it possible to write strongly reflective gratings even into standard telecommunication fibers. However, the mechanism is not yet clearly known. On the other hand, photosensitive absorption band (~240 nm) of germanosilicate fiber can be excited by two-photon absorption (TPA) of blue-green light. It has been known that Hill gratings2 are formed by TPA of 488 (514) nm Ar-laser light. TPA in the blue-green region has been studied by index change, induced loss, and electron-spin resonance. However, effects of hydrogen loading on TPA have not been reported. Such studies are expected to contribute to clarify the mechanisms of hydrogen loading, and possibility of enhancement of photosensitivity in the blue-green region. Although one-photon absorption in hydrogen-loaded germanosilicate glass has been measured, the TPA obeys a different selection rule. Hence, TPA should not be determined by an analogy with one-photon absorption and therefore should be determined by direct measurement.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
