[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - All Passive KGW/Tm:YAP Raman Laser

摘要： High brightness sources in the 2-3 micron region are essential for many applications including wavelength selective microsurgery, material processing, and gas monitoring. Although there are some rare-earth ions which enable such laser sources like Tm, Ho and Cr, those suitable lasers do not tailor all this spectral range. Solid-state Raman lasers are one of the efficient methods enabling to extend the spectral span of high brightness sources. Over the last five years, this trend was also realized in the 2 micron region, using BaWO4 and YVO4 crystals as Raman gain medium. Having minor thermal lensing and high damage threshold KGd(WO4)2 (KGW) is another promising Raman crystal, implemented until now with 1064 nm and 532 nm. This crystal has two different Raman shifts (901 cm-1 and 768 cm-1), enabling to yield, by control of the polarization orientation, two different stokes wavelengths. Here we present, for the first time, an external-cavity configuration for an all Passive Raman laser, based on passive fundamental pump with a KGW crystal. The KGW being pumped by an end pump CrZnS passively Q-switched Tm:YAP laser emitting at 1935 nm. This laser seed modified from our previous work, in order to achieve the higher peak power for the non-linear effect to take place. The seed had a maximal energy pulse of 1.5 mJ, having a pulse duration of 17 ns at a repetition rate of 1.3 kHz resulting in a peak-power of 90 kW for an average power of 2.1 W. This Raman laser emitted at 2270 nm and 2350 nm having 150 and 104 mW average power, respectively. Pulse duration as short as 12.5 ns and a maximal peak-power of 14.35 kW obtained.