Infrared Laser Optical Parametric Study Gauges Of 3.8μm

Mid-infrared laser has important application value in many areas. The main method to produce mid-infrared laser is based on the quasi-phase-matched optical parametric oscillator technology.Firstly, From the three-wave interaction equation, the basic principles of birefringent phase matching and quasi-phase matching was analyzed in detail, and we analyzed their advantages and disadvantages. And the theory of the optical parametric oscillator based on MgO:PPLN was analyzed. From the dispersion equation, the principle of parametric oscillator tunable output was reported.Then, by using an atmospheric-pressure chemical vapor deposition method,7-layers graphene films as saturable absorbers are fabricated. The Nd:YVO4crystal was used as gain medium and graphene saturable absorption mirror was used for passively mode-locked device. When pump power reached8.0W,1.06μm CW mode locking ultrashort pulse laser was obtained, with the pulse width of518fs and the repetition rate of66.7MHz. Then, the type-Ⅰ LBO crystal was inserted into the cavity, and frequency doubled532nm CW passively mode-locked ultrashort pulse laser was realized successfully. Stable ultrashort green laser pulses as short as374fs are measured with a repetition rate of71.4MHz. It turned out that this graphene was with excellent saturated absorption characteristics for stable and reliable passively mode-locked pulse generation.An efficient source of all solid-state tunable mid-infrared radiation based on a periodically poled MgO-doped lithium niobate (MgO:PPLN) optical parametric oscillator (OPO) is reported. The MgO:PPLN crystal was pumped by1064nm CW mode locking ultrashort pulse laser, the mid-infrared radiation optical parametric oscillator (OPO) was realized successfully. Then, the graphene saturable absorption mirror and the acousto-optically Q-switched be used as actively Q-switched. The MgO:PPLN crystal was pumped by1.06μm pulse laser. When temperature of the nonlinear crystal was177℃, and the cycle of this crystal is29um, the Idler wavelength is3.8μm. By changing the temperature of the crystal, a tunable mid-infrared spectrum from3783nm-3838nm was obtained.