Studies on Nonlinear Mechanisms of Excimer Laser Propagation in Fused Silica Fibers

摘要

This study was to investigate the potential for short wavelength generation through Raman upconversion in ultraviolet transmitting fibers. The study resulted in three key achievements: 1. Identification of induced absorption in fused silica UV fibers due to color center formation with the excimer laser at 193 nm. Optical bleaching to reverse the induced absorption was observed by using a longer wavelength of the excimer laser (XeF at 351 nm). A maximum recovery of 70% of initial transmission was obtained. This is the first time that color center formation and subsequent bleaching has been reported in UV transmitting fibers. 2. Development of new means to image single pulses from the excimer laser, utilizing a phosphor to down convert the image to videorecorder. 3. Study of Raman upconversions using excimer lasers. Comparison was made of fibers vs. Raman resonators. Limited coherence length because of the bandwidth spread of excimer lasers and unavailability of low-mode-number UV fibers are reasons why the Raman resonator appears to be a reasonable approach.