First-Stokes Wavelengths at 1175.8 and 1177.1 nm Generated in a Diode End-Pumped Nd:YVO₄/LuVO₄ Raman Laser

A diode end-pumped acousto-optic Q-switched Nd:YVO ₄ /LuVO ₄ Raman laser is demonstrated. Both YVO ₄ and LuVO ₄ can work as Raman gain, and slightly different active vibration modes of both crystals can result in different first-Stokes wavelengths. The output characteristic as the Raman competition between YVO ₄ and LuVO ₄ crystals for the laser systems with both shared cavity and coupled cavity is experimentally investigated. For the shared cavity, simultaneous Raman conversion in both YVO ₄ and LuVO ₄ crystals is achieved with dual-wavelength emission at 1175.8 and 1177.1 nm. The maximum output power of 1.03 W and the conversion efficiency of 10.3% are obtained. The 0.84 W single first Stokes wavelength at 1177.1 nm with LuVO ₄ Raman conversion is achieved with the coupled cavity. The results show that the coupled cavity with short Raman cavity can obtain a narrow pulse width. The separated laser crystal and Raman gain media with different vanadates in shared cavity have advantages in achieving dual-wavelength lasers with small frequency intervals. (paper)