Kinetics of defect centers formation and photosensitivity in Ge-SiO2 fibers of various compositions

Abstract

It was reported that the Ge E' center is related to second harmonic generation (SHG) in Ge-SiO21. Since the Ge E' center is known as hole-trapping center, this suggests that the positive charge trapping sites for SHG in Ge-SiO2 are Ge E' centers. However, in a later, detailed thermal stability study, we reported2 that only a variant of the Ge E' center, i.e., Ge E’d1, has thermal stability similar to SHG. This suggests that not all of the observed Ge E' centers are charged.