Abstract
A novel, compact and monolithic Electro-Optic periodically poled lithium niobate (PPLN) Bragg modulator with tunable quasi-phase-matching PPLN has been successfully demonstrated in this thesis. In the experiments, an active Q-switched 1064nm laser pumped by 808 nm diode laser with a-cut 0.25% doped Nd:YVO4 crystal has been constructed with an EO Bragg modulator firstly. The dimension of the EO Bragg modulator is 17mm (L) x10mm (W) x0.78mm (d) with grating period Λ=20.1μm and the corresponding half-wave voltage is 160V. The maximum output energy of the AQS laser reaches 198.7 μJ under 19.35-W pump power at 1 kHz repetition rate. The loss modulation of the EO Bragg modulator is temperature insensitive by 2.4% loss deviation from room temperature to 180℃. According to this feature, a cascaded OPG/SHG nonlinear conversion section with EO Bragg modulator has an opportunity to actualize. We used the AQS 1064 nm laser generated by EO Bragg modulator and injected into the nonlinear conversion QPM sections to proceed the OPG/SHG process. A tunable wavelength laser from 1797 to 2608 nm was generated by tuning the phase-matching temperature from the 100℃ to 168℃. The dimension of OPG section is 30mm (L) x7mm (W) x0.78mm with grating period Λ=31μm. The output signal pulse energy was approximately 30 μJ and the conversion efficiency was held at 17% under different phase matching temperature. The SHG process was executed on the same chip with the 30 mm (L) x5 mm (W) x0.78 mm and grating period was Λ=19.5μm for 3rd order SHG process. The maximum conversion efficiency was 30% under 6kW peak pump power. Due to the photorefractive damage, the maximum 532nm average power was clamped at 18 mW.