A microscopic model is given to explain the irreversible changes in glass fibers caused by simultaneous irradiation with 1064- and 532-nm light. The model involves an excitation of Ge E′ defects by photons of the fourth harmonic. A quantum-mechanical formalism is developed that is especially suited to describe a system under the influence of radiation fields.
© 1990 Optical Society of America
B. Lesche, "Microscopic model of second-harmonic generation in glass fibers," J. Opt. Soc. Am. B 7, 53-56 (1990)