Wavelength dispersive gain element for a tunable laser
Abstract
A tunable laser is described in which the gain element is fabricated to produce wavelength dispersion within the laser resonator cavity. Specifically, the laser gain element has Brewster angled entrance and exit faces which allow it to operate as a wavelength dispersive element while simultaneously performing the functions of an optical gain element within a laser cavity. Wavelength tuning is effected by angular rotation of one of the end reflective elements in the cavity. By using suitable dispersive materials for the laser gain element no additional tuning elements are required providing high efficiency, low threshold laser operation for a variety of optical excitation methods. The laser gain element replaces other discrete intracavity laser tuning means required for tunable lasers, including prisms, diffraction gratings, and birefringent filter elements. Solid state crystalline laser gain elements which are doped with impurity ions for laser operation are highly suitable for this type of laser, as are ion doped glasses or other amorphous materials. In addition, a suitable laser gain element can be constructed of a hollow fluid-containing cell where the cell is fabricated in the shape of a Brewster dispersing prism and the cell is filled with a laser gain fluid such as a dye solution or a chelate solution. Optical exciting means and geometries are discussed, as are the conditions for minimizing astigmatism introduced by the prism.
- Publication:
-
Patent Department of the Navy
- Pub Date:
- April 1994
- Bibcode:
- 1994navy.reptQQ...S
- Keywords:
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- Cavity Resonators;
- Laser Cavities;
- Light Amplifiers;
- Tunable Lasers;
- Dye Lasers;
- Optical Pumping;
- Patents;
- Solid State Lasers;
- Lasers and Masers