Abstract

Spatial homogeneity of the gain along the direction of propagation of the signal beam in longitudinally pumped laser or amplification mediums is important to guarantee bandwidth conservation in chirped-pulse amplification and to optimize the extraction efficiency for high-intensity applications. For one-photon excitation this homogeneity can be improved by double-sided pumping or end-pumping with an appropriately focused beam. Spatial homogeneity of the gain along the direction of propagation of the signal beam in longitudinally pumped laser or amplification mediums is important to guarantee bandwidth conservation in chirped-pulse amplification and to optimize the extraction efficiency for high-intensity applications. For one-photon excitation this homogeneity can be improved by double-sided pumping or end-pumping with an appropriately focused beam. For two-photon excitation with ultrashort pulses an interesting high-intensity situation exists, in which pump depletion due to strong absorption counteracts self-focusing, resulting in a nearly constant gain along the propagation direction.

© 1993 Optical Society of America