Parasitic oscillation suppression in solid state lasers using absorbing thin films
AssigneeThe United States of America as represented by the United States Department of Energy
InventorLuis E. Zapata
Life of this patent
Estimating the term…
Abstract
A thin absorbing film is bonded onto at least certain surfaces of a solid state laser gain medium. An absorbing metal-dielectric multilayer film is optimized for a broad range of incidence angles, and is resistant to the corrosive/erosive effects of a coolant such as water, used in the forced convection cooling of the film. Parasitic oscillations hamper the operation of solid state lasers by causing the decay of stored energy to amplified rays trapped within the gain medium by total and partial internal reflections off the gain medium facets. Zigzag lasers intended for high average power operation require the ASE absorber.
Claims15
A material comprising:
- (a) a solid state laser gain medium;
- and
- (b) an absorbing thin film bonded to at least certain surfaces of said gain medium wherein the index of refraction of said thin film is greater than or equal to the index of refraction of said gain medium and wherein said thin film is selected from a group consisting of germanium, silica, dried graphite ink, semiconductor material, a halide and dysprosium.
In a laser having a solid state gain medium, the improvement comprising:
- an absorbing thin film bonded onto at least certain surfaces of said gain medium where a laser beam does not impinge, wherein said thin film is selected to allow transmission of light from an excitation mechanism, wherein said thin film is selected from a group consisting of germanium, silica, dried graphite ink, semiconductor material, a halide and dysprosium, wherein the index of refraction of said thin film is greater than or equal to the index of refraction of said gain medium and wherein the thin film is positioned to frustrate total internal reflection of amplified stimulated emission and parasitic lasing without substantially suppressing a laser beam propagating through the gain medium.
Dependencies are inferred from the claim text.