The diode-pumped continuous-wave Raman laser: Classical, quantum, and thermo-optic fundamentals

This thesis describes the creation and development of far-off-resonance diode-pumped cw Raman lasers using high-finesse cavity enhancement from both theoretical and experimental standpoints. Comprehensive theoretical models are developed for the cw Raman system in the classical and quantum mechanical domains. The classical treatments include two separate derivations of the time-dependent cw Raman equations (one as an appendix), derivations of the analytical steady-state threshold power, impedance-matching power, all emitted powers, and conversion efficiency, as well as the system optimization with respect to every parameter available, and a useful frequency tuning picture (as an appendix). An entire chapter is devoted to the classical treatment of thermo-optic effects in this laser system including mode pulling and thermal lensing.; The quantum mechanical treatment uses the Heisenberg/Langevin approach to derive the Stokes output noise spectra analytically for this system. Subsequent analysis reveals the possibility of approaching perfect photon statistics transfer from the pump to the Stokes and generating nonclassical photon number statistics. An interesting and useful connection to the nondegenerate optical parametric oscillator is uncovered. The quantum mechanical approach is also used to show that a similar system can generate efficient cw anti-Stokes emission.; The process of constructing these laser systems and the subsequent measured behavior comprise the experimental component of this thesis. Diode laser frequency locking for this system is treated thoroughly as an exercise in precision frequency stabilization and control theory. The optimal designs of the diode laser pump source, the high-finesse Raman laser cavity, and the electronic servo are discussed. The use of injection locking and passive optical frequency stabilization are also addressed.; Using these construction and locking techniques, the results from diode-pumped cw Raman laser experiments in diatomic hydrogen gas are provided and are shown to compare favorably with the theoretical predictions. The results include steady-state data obtained from the first diode-pumped cw Raman laser, the first high efficiency cw Raman laser, a cw Raman laser pumped by an injection-locked diode laser, and the first cw Raman ring laser. Data confirming the effects of thermal mode pulling and lensing are also provided.