Abstract

Strong spatial hole burning (SHB) leads to a strong coupling of all of the up to a thousand laser modes within the gain bandwidth of the laser medium. End-pumped solid-state lasers that exhibit strong SHB are usually pumped more than a hundred times above threshold^1-3 are no longer applicable. Recently, some aspects of spatial hole burning on pulse shortening in a mode-locked laser has been treated by C. Flood et al.⁴ Their analysis is based on a gain-grating model developed for investigation of pulse shortening in colliding-pulse mode-locked dye lasers. However, a slowly varying sinusoidal gain grating is assumed and that does not correctly describe the nonsinusoidal gain grating of a solid-state laser pumped many times (≈100) above threshold. We implement the optical gain for arbitrary pumping levels and especially for the gain medium at the end of the cavity making extensive use of the fast Fourier transformation.⁵

© 1996 Optical Society of America