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Q-switched microchip lasers are very compact sources of directional radiation. To construct such a radiation source in the 1.3 μm spectral region, Nd:YAG active medium with V:YAG saturable absorber can be used. Radiation in this spectral range is safer for the eye in comparison with 1.06 μm radiation due to its higher absorption in the water. For this reason, Nd:YAG/V:YAG microchip laser could be suitable for free-space light manipulation applications such as LIDARs. Nd:YAG/V:YAG microchip lasers and optimization of their output parameters based on diode-pumping beam parameters variation are presented here. For this optimization, aspheric lenses were used, which made it possible to increase the pumping beam area in the waist more than four times from 0.13 mm2 to 0.58 mm2. Two Nd:YAG/V:YAG microchip lasers with a total length of 2.6 mm and 4.7 mm were tested. In both cases, the initial transmission of the V:YAG saturable absorber was 80 % @ 1.34 μm and the output coupler reflectivity was 90 % @ 1.34 μm. Lasers were pumped longitudinally by a fiber-coupled laser diode (core diameter 400 μm, numerical aperture 0.22) in a pulse regime at a wavelength of around 805 nm in the range of repetition frequencies of 10 − 1000 Hz. Both Nd:YAG/V:YAG lasers provided Q-switched pulses at a wavelength of 1338 nm. By increasing the pumping beam area it was possible to achieve almost twice as high pulse energy and peak power up to 76 μJ and 85 kW using a 2.6 mm long laser. In the case of a 4.7 mm long laser, the pulse energy and peak power increased more than four times up to 139 μJ and 84 kW. The output pulse duration hardly depended on used pumping optics and its mean value was 0.92 ns/2.6 mm and 1.91 ns/4.7 mm. Higher spatial transverse modes were not observed for most pumping pulse repetition frequencies.
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