Study Of All-solid-state1.57μm Optical Parametric Oscillators

All-solid-state1.57μm Optical Parametric Oscillators(OPO) are characterized as eye-safe, long life, high efficiency, small size and compact structure, which can be used in high pulse repetition frequency laser rangefinder, lidar and laser scanning imaging. So they have a bright and broad prospect.Based on the theory of optical parametric oscillators, we chose Nd:YAG/Cr4+:YAG bonding crystal and nonlinear KTP crystal as laser medium and OPO crystal. First, a experimental prototype machine was built, and the key problems of design were verified, such as how to place KTP crystal and so on. And then we developed a small OPO engineering prototype machine. At an incident diode pump of4W, a maximum1.57μm light output power of120mW was achieved at the pulse width of Ins and the pulse repetition rate of8.2kHz. The power stability was11.4%and the whole machines dimension was95x93x75mm3.All the properties of the laser were fit for the project demands. The size of the prototype machine was reduced to82×25×25mm3after further optimization, while the output indexes were the same. On this basis, we proposed the method to improve stability and did preliminary research.