Principles and Applications of Optical Monolithic Total Internal Reflection Resonators

Efficient externally resonant continuous-wave frequency conversion in bulk nonlinear crystals requires low-loss optical resonators. To reduce the losses, cost, and limitations inherent in discrete-component resonators, a novel type of resonator, the monolithic total internal reflection resonator (MOTIRR), has been developed. It is based on confinement of the resonator mode by total internal reflection (TIR) only, rather than by dielectric mirrors, thereby minimizing reflection losses. This dissertation discusses characteristics and applications of linear and nonlinear MOTIRR's. A theoretical and experimental study of the whispering -gallery mode spectrum of a 1.9 cm radius fused silica spherical MOTIRR is presented. Variable input/output coupling into MOTIRR's is achieved by frustration of TIR (photon tunneling) using a coupling prism. The resulting gap-dependent transfer function has been measured on a 1.4 cm ring length fused silica MOTIRR and good agreement with theory was found. Nonlinear MgO:LiNbO_3 MOTIRR's with 3.2 and 1 cm ring length were fabricated. The latter exhibited 0.2% loss at 1.06 mum, the lowest value demonstrated in a nonlinear resonator to date. Since TIR is not wavelength-selective, MOTIRR's can support resonant oscillation of waves of widely varying wavelengths. Second -harmonic generation (SHG) resonant at the subharmonic and harmonic yielded 15 mW internally circulating harmonic power for 1 mW input power at 1.06 mum. The circulating harmonic caused internal doubly-resonant parametric oscillation. The threshold of this quadruply resonant parametric oscillator (QRO) was 0.4 mW at 1.06 mum. Nonlinear MOTIRR's should prove useful for widely tunable resonant frequency conversion, the study of nonlinear dynamics in doubly-resonant SHG, and the generation of non-classical light. Finally, optical clocks and displacement sensors using linear MOTIRR's are proposed.