Lasers operating around 1.5μm locate within the absorption band of water molecules and the characteristics of eye safety. For this reason,1.5μm eye-safety lasers have the application foreground in the fields involving bio-medicine, optical communication, precision measuring and laser-guided weapons, etc. Optical parameter oscillator (OPO) has advantage of tunability, the tunable range can be from ultraviolet to far infrared, which makes up the disadvantage of the common lasers only emitting a single wavelen...