Output Performances Of Stimulated Raman Scattering Laser In Tm,Ho:GdVO₄Crystal

Owing to their compactness, high conversion efficiency and good beam quality,solid-state lasers have attracted great attention. The near-infrared laser is widely used inoptoelectronic countermeasures, gas sensing and so on. However, little research on the2.5μmlasers has been reported. Stimulated Raman scattering （SRS） is a promising pathway forgenerating lasers around2.5μm.In this thesis, the Tm,Ho:GdVO₄pulse laser is selected as a pumping source, a BaWO₄Raman crystal is applied as the gain medium to observe Raman lasers. A stimulated Ramanscattered frequency shift of around924cm-1is expected in the BaWO₄crystal. TheTm,Ho:GdVO₄crystal which is cooled by liquid nitrogen is pumped by a laser diode （LD） togenerate2.05μm continuous laser. The cavity parameters are optimized to obtain highefficiency continuous laser. The active Q-switch scheme is utilized, so that arepetition-rate-adjustable pulse laser with high pulse energy is obtained. The pulse laser canalso be optimized by adjusting the cavity parameters, such as the cavity length and thetransmittance of the output coupling mirror. Due to the high threshold of the Raman crystal,intracavity with high energy density and high conversion efficiency is applied in thestimulated Raman scattering experiment. A Raman laser with an output wavelength of2.5μmis obtained. The average output power, single pulse energy, pulse width and other Raman lasercharacteristics that vary with the cavity parameters are analyzed.Solid-state Raman lasers generated by stimulated Raman scattering with an outputwavelength of2.5μm is demonstrated for the first time. At a repetition rate of4kHz, amaximum average output power of730mW is obtained. The maximum pulse energy is312μJ, the peak power is78kW, the light-light conversion efficiency is about6.6%, and thehighest slope efficiency is around22.5%.