Nonlinear Optics: Parametric Amplification at 16 Micrometers and Oscillator Mode Competition

摘要

Parametric amplification in the 16- mu m region in Brewster-cut CdSe is reported. An HF pump laser with a flat radial intensity profile was used, thereby eliminating the need for confocal focusing of pump and signal beams. Plane-wave analysis is therefore used. The gain bandwidth was determined and found to be in agreement with theory. The second-order nonlinear susceptibility was measured for the first time at 16 mu m through Miller's delta . The frequency distributions for a parametric oscillator fitted with sapphire and ZnSe etalons have been measured and interpreted in terms of the probability of oscillation for specific cavity modes. A theoretical model is developed to calculate these probabilities. It involves finding local approximate analytical solutions of the coupled mode amplitude equations of A. Yariv and W.H. Louisell in Theory of the Optical Parametric Oscillator, IEEE JQE, QE-2, 418 (1966). The solutions are then interpreted statistically. Predictions of the model are compared with the measurements. Reasonable agreement is found. (ERA citation 04:050440)