Portable source of high-power short pulses at a wavelength of 532  nm based on an Nd:YAG/Cr:YAG crystal microchip laser pumped by an array of multiwavelength laser diodes

Subject of study. The second-harmonic generation of radiation from an experimental microchip laser developed previously and improved in this work is studied. Aim of study. The aim of this study is to obtain second-harmonic generation from a compact microchip laser with high peak power and pulse energy. Method. The efficiency of nonlinear optical conversion was increased by the high peak power of laser radiation. Deposition of the cavity mirrors directly onto the end faces of the active element simplified the laser design. A multiwavelength laser diode array was used as the pump source. An optical collimation system was employed to improve the efficiency of pump radiation. Main results. Second-harmonic generation was obtained at a wavelength of 532 nm with a conversion efficiency of 32% using an Nd:YAG/Cr:YAG microchip laser operating without a thermal stabilization system. The obtained radiation pulses exhibited high amplitude stability with pulse energies of 5 mJ at 1064 nm and 1.6 mJ at 532 nm. Multipulse generation regimes were observed with increasing pump pulse duration. Practical significance. The obtained results enable the development of portable sources of high-power short optical pulses for applications in materials processing, spectroscopy, optical ranging, atmospheric sensing, and investigations of new nonlinear optical materials.