New High Power Laser Medium Index Matching Reduces Parasitic Lasing in Cryogenic Environments

Abstract

UCF researchers have developed an innovative method that reduces and/or eliminates gain clamping in a solid-state laser and amplifier systems and works with other index-matching methods. The design works well with standard cladding/coating materials that employ either tunable index of refraction or tunable absorption materials and with materials that have no existing index-matching procedures available. This technique can also be used as part of an amplifier offering the benefits of both cryogenic cooling and anti-transverse lasing.

Technical Details

This novel system provides a solid-state laser/amplifier gain medium that prevents parasitic lasing and is compatible with operation in evacuated and cryogenic environments. The gain medium is comprised of a perimetrical edge with an ASE-absorbing epoxy composition, with an index refraction that matches the gain medium's index of refraction, applied on a portion of the edge. By bonding a light-absorbing, refractive index-matched material to the edges of the laser gain medium, the ASE in the transverse direction can be coupled out to prevent the build-up of parasitic oscillation. This technique reduces the strength of the Fresnel reflections and adds high absorption losses, both of which increase the losses in the transverse direction. Different epoxies with high and low refractive indexes are combined in predetermined amounts to create an optical refractive index that closely matches the laser gain medium. To enhance the absorption power, superfine metal particles with absorption at ASE wavelengths may be added to the epoxy base.

Benefit

Market Application