Passively Q-switched multiple visible wavelengths switchable YVO4 Raman laser

Abstract

The output characteristics of orange-yellow-green emission switchable output generated in a compact passively Q-switched YVO4 Raman laser were investigated for the first time. A Cr4+:YAG/YAG composite crystal was adopted as the saturable absorber to realize passively Q-switch operation. The diode-end-pumped Nd:YAP laser operating at 1.08 μm was used to drive an a-cut YVO4 crystal for realizing the first-Stokes wavelength at 1.2 μm. Selective frequency mixing of the first-Stokes and the fundamental waves in a shared cavity were achieved by an angle-tuned BBO crystal. Under an incident pump power of 12.05 W, the average maximum output powers of 472 mW for 597.4 nm orange light, 431 mW for 567.2 nm yellow light and 803 mW for 539.9 nm green light could be switchable output with respective pulse widths of about 2.6, 2.4 and 37.6 ns. Under the maximum incident pump power, the pulse repetition frequency and the single pulse energy were approximately 11.6, 10.9, 13.4 kHz and 40.7, 39.5, 59.9 μJ, respectively.