A frequency doubled gain switched Yb3+-doped fiber laser

Abstract

ABSTRACT In this paper we present for the first time to our knowledge an efficient and rugged light sour ce in the visible, based on a gain switched Yb 3+ doped fiber laser source, frequency doubled by a non-critically phase matched LiB 3 O 5 crystal. The simple setup proves to be robust and durable against back reflections, which in turn remove the requirement for optical isolators along most of the system. Gain switched fiber lasers typically produce long pulses with low peak power, which are not optimal for frequency conversion applications. However, as opposed to MOPA laser configurations, based on a semiconductor laser diode as a seed source, the narrow spectral line width and chirp free operation of gain switched lasers render them suitable for efficient frequency doubling. Keyword : pulsed fiber lasers, gain switching, non-linear frequency conversions INTRODUCTION Recent development of high peak power pulsed fiber lasers and the availability of robust industrial grade linearly polarized fiber lasers, have been of great interest for frequency doubling into the visible range. The combination of simplicity, high efficiency, high beam quality and robustness, render fiber lasers to be a preferred alternative for frequency doubling. Several successful works on frequency doubling of Yb