In recent years, a 1μm DPSSL has achieved high power and highly efficient operation with good beam quality. This progress of DPSSL and improvement of the wavelength converter are expanding available wavelength range of solid state lasers. In particular, introduction of periodic poled materials as wavelength converter enables low peak power solid state laser to convert the wavelength efficiently. A periodic-poled lithium niobate (PPLN) is a first widely applied QPM material because of its large effective nonlinear coefficient (>15pm/V) and relative large transmission wavelength range (0.32-5μm).