Laser Diode-Pumped Tunable Solid State Laser.
Patent, filed 10 Jan 91, patented 1 8 Feb 92,
DEPARTMENT OF THE NAVY WASHINGTON DC
Pagination or Media Count:
A low threshold resonator for an alexandrite laser receives a 680 nm pumping beam from at least one laser pump to provide alexandrite laser emission at around 751 nm. An alexandrite crystal or rod receives the 680 nm beam and has an exterior face provided with a dichroic coating highly transmissive to the 680 nm beam and highly reflective to the 751 nm emission and has an interior face provided with an AR coating antireflective to the 751 nm emission. A mirror, provided with a HR coating that is highly reflective to the 751 nm emission, has an appropriate radius of curvature and is appropriately spaced from the exterior face of the alexandrite rod to focus reflected 751 nm emission in a resonator mode on the exterior face of the alexandrite rod to assure low threshold pumping thereof. The mirror has a radius of curvature which is the same as the spacing between the exterior face of the alexandrite rod and the mirror to focus the reflected emission in the resonator mode in a spot size on the exterior face. A lens is disposed to receive the pumping beam to focus it on the spot size on the exterior face of the alexandrite rod. The lens, the alexandrite rod and the mirror are appropriately configured and predeterminably spaced with respect to each other to assure that mode matching of the lens expands at exactly the same rate as the resonator mode to assure low threshold pumping thereof.
- Lasers and Masers