Abstract
Photosensitivity in germanosilicate fibers has been known to relate to 240-nm absorption band of Ge-related oxygen-deficiency defects. In the blue-green region, Hill-grating formation and second- harmonic generation are attained by two- photon (multiphoton) absorption. However, the spectral dependence of two- photon absorption (TPA) coefficients has not been made clear. The 240-nm absorption and the photosensitivity have been attributed mainly to Ge-Si (or Ge-Ge) defects. However, the density of Ge2+ (=Ge:) defects is two orders of magnitude higher.1 We have previously shown that Ge2+ defects are dominant for UV-induced refractive index changes.2 Here we measure the TPA spectrum of germanosilicate fiber and discuss the origin of TPA.
© 1996 Optical Society of America
PDF ArticleMore Like This
Toru Mizunami, Masato Hashimoto, Mamoru Yamashiro, Sanjay Gupta, and Teruo Shimomura
SuA.5 Nonlinear Guided Waves and Their Applications (NP) 1996
Toru MIZUNAMI and Keiji TAKAGI
MB.1 Nonlinear Guided-Wave Phenomena (NP) 1993
D. P. Hand, L. J. Poyntz-Wright, and P. St. J. Russell
MJ3 Integrated Photonics Research (IPR) 1990