Abstract
Periodically poled lithium niobate (PPLN) was an essential element which has plenty of benefits for tunable coherent radiation from ultraviolet to mid infrared. Laser sources based on PPLN are used of many applications. However, a narrow spectral linewidth is usually difficult to achieve in PPLN lasers. Although optical parametric oscillator (OPO) and amplifier (OPA) are capable of producing narrow-linewidth radiations, the configurations are complex and expensive. In this dissertation, we establish a theory of a novel PPLN laser, distributed feedback (DFB) OPO. The performance of a DFB OPO, including the pump dependent mode and gain spectrum are simulated in the dissertation. Such a laser is proved to achieve single frequency operation but still with wavelength selectivity.The fabrication of PPLN waveguides is also interesting since high power conversion efficiency; continuous wave infrared radiation is desired in many applications, such as spectroscopy and tele-communication. If one can integrate DFB structure to a PPLN waveguide, the generation of high-efficiency, single-frequency, and low-threshold DFB PPLN OPO becomes possible. A common way of fabrication PPLN waveguide is the annealed proton exchange (APE) process. In this dissertation, we used the APE process to fabricated channeled PPLN waveguides. We characterized the performance of the APE waveguide by monitoring the second harmonic efficiency of a 1550-nm external cavity laser (ECL) amplified by an erbium doped fiber amplifier (EDFA). After the optical characterization, distributed feedback structures are fabricated on the PPLN waveguide by sputtering silicon dioxide atop the surface of the PPLN waveguide.