Yellow, lime and green emission selectable by BBO angle tuning in Q-switched Nd:YVO₄ self-Raman laser

A wavelength-selectable visible emission from an acousto-optic Q-switched Nd:YVO₄ self-Raman laser was demonstrated. A BBO crystal was adopted as a nonlinear optical crystal to realize second harmonic generation or sum frequency generation in the self-Raman cavity by angle tuning, resulting in the output on demand of yellow, lime and green laser with quick switching. Under an incident pump power of 10.2 W and a pulse repetition frequency of 60 kHz, maximum output power of 2.05, 0.81 and 1.73 W were achieved for the 532, 559 and 588 nm lasers, respectively. This laser system can provide a compact and convenient method to achieve the wavelength-selectable pulse visible emission for application as biomedical diagnostics, visual displays, etc. (letter)