PHOTOINDUCED BIREFRINGENCE ROTATION IN GERMANOSILICATE GLASS OPTICAL-FIBER

Experimental results are reported for the permanent photoinduced rotat ion of the principal axes of the birefringence in a circular-core sing le-mode optical fiber on exposure of the fiber to powerful argon-laser radiation at 488 nm. The linearly polarized laser beam was launched i nto the fiber along one of the principal axes of the initial birefring ence in the fiber. After several exposures totaling 4 h, a rotation of as much as 57-degrees was observed in the orientations of the princip al axes in addition to the photoinduced birefringence.