Requirements are imposed on unstable resonators designed for high-energy laser operation which would not normally be considered for low-energy operation. For chemical lasers these requirements arise primarily because of the short mode width characteristics of the laser medium. Also, the resonator performance is strongly dependent on the selection of the active medium height and length. The high aspect ratio resonator mode may be dominated by diffraction effects in the shorter dimension. Attendant to the diffractive effects is a high sensitivity to mirror misalignment and a need to establish good resonator mode control. When these potential problems are coupled with the usual resonator requirements of high extraction efficiency, acceptable beam quality, and optical compatibility, the range of resonator design parameter space is found to be significantly reduced from that available to low-energy laser resonators. It is, therefore, desirable to develop a screening technique which clearly identifies the range of resonator parameter space available to high-energy lasers.
© 1984 Optical Society of AmericaPDF Article