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The progress of optical parametric oscillator based on LiNbO3 crystal

The MgO:PPLN-based QPM OPO is one of the most important method to generate mid-infrared laser. In this paper we attempt to briefly overview the historic development of LiNbO3 crystal and introduce the theoretical foundation of MgO:PPLN-based QPM OPO. We subsequently give a analysis of different kinds of MgO:PPLN-based QPM OPO. The wavelength region of 3-5 μm (belonging to the mid-infrared) is important atmospheric window in the optical spectrum. The mid-infrared lasers have drawn enormous interest and obtained a variety of applications, such as, air pollution detection, optical fiber communication, military countermeasures, and so on. In recent years, along with the emergence of lots of nonlinear materials (such as AgGaS2 and AgGaSe2, KTP and KTA, ZnGeP2, LiIO3, LiNbO3), it’s become easier to obtain mid-infrared lasers. Because of those new nonlinear materials can satisfy the follow conditions, large nonlinearity, transparency in operating wavelength range and high damage resistance. Among those nonlinear materials, the LiNbO3 (LN) crystal is one of the most suitable materials to be used to obtain mid-infrared laser.