Influence of Pump Pulse Duration on the Output Performance of a LED-Pumped Nd:YAG Laser

Abstract: In this paper, we performed an experimental study of a LED-pumped Nd:YAG laser that works in QCW and Q-switch modes. We examined how the pump pulse duration affects the laser output. The laser rod was a Nd:YAG crystal with a diameter of ۷ mm and a length of ۹۵ mm, side-pumped by ۳۰ LED arrays, each with ۱۸ single dies at ۸۱۰ nm. The maximum output energy at ۱۰۶۴ nm was ۱۰.۵ mJ in the QCW mode, with a pump energy of ۸۱ mJ (۲۳۰ µs pulses at ۱ Hz). The optical conversion efficiency and the slope efficiency were ۱۲.۵% and ۱۸%, respectively. In the PQS mode, the output energy was ۲۵۰ µJ, with a pulse width of ۱۹۰ ns (FWHM), corresponding to a peak power of ۱.۳۱ kW. The beam divergence was ۰.۳ mrad with TEM۰۰ mode. This LED-pumped Q-switched Nd:YAG laser can be used for laser range finder applications.