Abstract
This research focuses on simulating and designing a chip with periodic poled congruent grown lithium tantalite to achieve the goal of multiple harmonics generation simultaneously so as to expand the range of spectrum of the laser wavelength. With the technique of waveform synthesis, this chip will allow us to obtain ultrashort subfemtosecond pulses. It will make the ultimate goal of controlling electronic motion closer to reality. The thesis includes a short summary of the theory of optical parametric oscillator (OPO) and quasi-phase matching (QPM), simulation and design of the nonlinear crystal, measurement results and analysis. At last, there is an attachment about the conversion efficiency measurements of crystals designed for a programmable full-spectrum laser wavelength conversion system. In the first part, we introduce frequency conversion, OPO and QPM. In the part of measurement and design, we calculate the phase-matched periods, test the fan-out chips and simulate conversion efficiencies to decide on the periods and lengths of every section on a QPM chip that can be sued for multiple harmonics generation. We successfully designed and fabricated a chip that can generate seven harmonics. In the last part, we describe the measurement of the conversion efficiencies of sum frequency generation (SFG) and difference frequency generation (DFG) of a CW fiber laser and a 1550 nm laser diode for the purpose of building a programmable tunable laser source. The conversion efficiency of DFG is 1.21% which is higher than any reported in the literature.