ABSTRACT
The theory of optical parametric processes in a nonlinear medium follows the earlier work of Armstrong et al. and has been reviewed by many authors. This chapter focuses on the essential points. Depletion and later recovery of the pump beam can occur in the process. The spatial and temporal profiles of a pump pulse can have profound effect on the conversion efficiency of an optical parametric device. Optical parametric amplification is a three-wave mixing process, in which a pump beam, a signal beam, and an idler beam at frequencies, propagate and interact in a nonlinear medium. For the case of appreciable energy exchange between waves, a split-step Fourier transform technique has been developed. It is based on the assumption that in propagating the waves over a small distance, the diffraction and nonlinear interaction of waves can be treated independently.
