Tunable pulsed titanium:sapphire laser and conditions for its operation

Abstract

A laser system for producing pulsed, longitudinal mode optical energy over a widely tunable range of wavelengths. The system includes an optical cavity and a solid-state gain medium. The optical cavity comprises first, second, and third optical element means. The first optical element means reflects energy received along a first reflective optical axis and directs the energy toward the second optical element means, which diffracts the optical energy into at least two orders of interference. The energy diffracted according to a first order of interference is reflected back toward the second optical element means by a third optical element means, thereby creating a resonant optical cavity. Another portion of the optical energy diffracted by the second optical element means is produced as an output beam. The solid-state gain medium is located on the optical axis between the first and second optical element means and receives pump energy from a plurality of pump beams that are within two degrees of being colinear with the first reflective optical axis. The solid-state gain medium converts the pump beam energy to optical energy having a desired wavelength with a very high efficiency, without required pump beam energy densities above a predetermined level. The laser system is tunable by moving the third optical element means with respect to the second optical element means, thereby causing optical energy at a tunable wavelength to resonate within the optical cavity.