Inventors:
James J. Kilcy - Binghamton NY
International Classification:
H01S 303
Abstract:
A beam of coherent light is generated in a 360. degree. pattern about a central axis perpendicular to the beam, either outwardly from or inwardly toward the axis, without requiring moving parts. The beam is introduced into the space between concentric, cylindrical surfaces, both reflective to some extent, but one more highly reflective than the other, with respect to the wavelength of the beam. After multiple reflections between the surfaces, the beam passes through the less reflective surface about the entire 360. degree. circumference thereof. In a first embodiment the beam is generated by a conventional laser, or the like, and directed along an axis which perpendicularly intersects the axis of a hollow tube having external and internal surfaces which provide the aforementioned multiple reflections. Reflectivity of essentially 100% by the inner surface may be provided by filling the hollow tube with mercury, or other highly reflective substances, and secondary optics may be arranged to provide more uniform intensity in each radial segment of the beam. In a second embodiment the beam is generated within the space between the reflective surfaces by pumping an active medium arranged therein to an energy level sufficient to produce lasing with the beam radiating outwardly through the larger diameter surface, or inwardly to the central axis through the inner surface.