Transmission of high-average-power XeCl laser radiation through fused silica fibers

Abstract

The feasibility of coupling in and transmitting high average power UV radiation down fused silica fiber without damage has been demonstrated in burst mode. The approach we have followed to transmit high average XeCl laser powers is to use modest laser energies at very high repetition rates, because the induced attenuation coefficient at high repetition rate is likely to be less than that which would occur using a high fluence modest repetition rate approach. We have also chosen to utilize a long optical pulse duration XeCl laser made possible using a magnetic-spiker excitation circuit. For a given laser fluence coupled into the fiber, the low peak power long pulses reduce the probability of intensity dependent effects such as catastrophic surface damage and color center formation. The influence of pulse duration, repetition rate and laser beam quality on fiber optic transmission will be discussed. An output average power of 75 W (in a burst mode) of XeCl laser radiation has been transmitted through a single step-index fused silica fiber using a high repetition rate (820 Hz), long optical pulse (180 ns (FWHM)) magnetic-spiker excited XeCl laser.