Multiple visible wavelength switchable cascaded self-Raman laser based on selective wave-mixing mechanism

A diode-pumped solid-state laser with watts-level five switchable wavelengths spanning green to red is first experimentally demonstrated. The selective wave-mixing mechanism was introduced for multiple visible wavelength switchable output. The five visible wavelengths are generated by wave-mixing of the fundamental wave, the first-Stokes wave, and the second-Stokes wave in a Nd:YVO4 self-Raman laser. A beta-barium borate crystal with a critical phase-matching angle cut is used for the wavelength conversion, and the angle-tuning method was used to achieve fast wavelength switching. A diffusion bonded YVO4/Nd:YVO4/YVO4 crystal was used to reduce the thermal lens effect and increase the effective length of the Raman gain medium for high output power and efficient Raman conversion. Under a pump power of 19.5 W, five visible laser output powers achieved for the green at 532 nm, lime at 559 nm, yellow at 588 nm, orange-red at 620 nm, and deep red at 657 nm are 4.01, 1.76, 2.54, 1.41, and 2.82 W, respectively. This laser system provides a convenient way for visible wavelength-switchable coherent light generation and may find potential applications where multiple visible wavelengths are required.