Orthogonally polarized dual-wavelength Nd:YVO4/MgO:PPLN intra-cavity frequency doubling green laser

An orthogonally polarized dual-wavelength laser emitting at 542 nm and 543 nm was proposed and demonstrated. The laser was based on a single Nd:YVO4 crystal and two MgO:PPLN crystals. An optical-to-optical (O-O) efficiency as high as 15.3% was achieved when the powers of the two emission wavelengths were equal. The long-term power stability was 4.5% for 542 nm and 3.5% for 543 nm, respectively. The Laser speckle contrast ratio (SCR) was also measured as a function of power ratio of the two emission wavelengths. The measured SCR values agreed with theoretical simulations with a difference less than 5%.