1) Optical material
Found on
https://www.crosswordclues.com/clue/photodarkening
Photodarkening is an optical effect observed in the interaction of laser radiation with amorphous media (glasses) in optical fibers. Until now, such creation of color centers was reported only in glass fibers . Photodarkening limits the density of excitations in fiber lasers. ==Definition== One could expect the term photodarkening to refer to any ...
Found on
http://en.wikipedia.org/wiki/Photodarkening
No exact match found.
