New Monte Carlo Method and Review of Present Methods For Calculating the Characteristics of Excitation Geometries for Solid-State Lasers

摘要

Excitation geometries which have been used to transfer pumping radiation from the source to the active medium of lasers are reviewed and literature cited. Methods of analysis and simplifying assumptions used to calculate the characteristics of excitation geometries are discussed. A three-dimensional Monte Carlo calculation which accounts for interactions that affect the pump light and its distribution in the cavity and active medium of the laser is presented. The calculation accounts for the spectrum, polarization, and intensity distribution of the pump light and the reflection and fraction of the cavity, source, and active medium. The photon trajectories are traced through multiple reflections and refractions by the components of the system until they are absorbed. Absorption in the active medium is based on the absorption coefficient as a function of frequency and on a ground state ion density where account is taken for excitation of active ions to the excited states and for return to the ground state by spontaneous and stimulated emission. Results are presented for various cavity and crystal geometries. (Author)