High repetition frequency and high energy Pr:YLF pulsed laser operating in single-longitudinal-mode

In this article, a single-longitudinal-mode pulsed laser with a center wavelength of 639.7 nm was developed by using a 444 nm laser diode end face continuously pumped Pr:YLF crystal, with the method of inserting the Q-switching pre-lase technology and a Fabry-Perot etalon set in the resonant cavity. Experimental results show that by optimizing the parameters of the inserted components in the laser cavity, the problem of single-longitudinal-mode oscillation during high energy injection being unstable can be solved. With the proposed laser, a Q-switching pre-lase single-longitudinal-mode pulsed laser output has been achieved with 10.25 μJ energy and 77.66 ns pulse duration at a repetition of 20 kHz. The spectral linewidth of the single-longitudinal-mode pulsed laser was approximately 18 MHz.