Abstract: A device includes a first sensor configured to generate a first output signal corresponding to an energy of a portion of a forward beam transmitted by a mirror of a laser resonator system. The device further includes a second sensor configured to generate a second output signal corresponding to an energy of a portion of a return beam transmitted by the mirror. A ratio of the energy of the portion of the forward beam and the energy of the portion of the return beam corresponds to a measurement of a feedback ratio of the laser resonator system.

Abstract: A device includes a first sensor configured to generate a first output signal corresponding to an energy of a portion of a forward beam transmitted by a mirror of a laser resonator system. The device further includes a second sensor configured to generate a second output signal corresponding to an energy of a portion of a return beam transmitted by the mirror. A ratio of the energy of the portion of the forward beam and the energy of the portion of the return beam corresponds to a measurement of a feedback ratio of the laser resonator system.

Abstract: An unstable laser disk resonator combines the output laser power of multiple laser disks to produce a high power, single transverse mode laser output beam, which is near diffraction limited.

Abstract: An unstable laser disk resonator combines the output laser power of multiple laser disks to produce a high power, single transverse mode laser output beam, which is near diffraction limited.

Abstract: A thermal imaging device comprises an array of microbridges(10) disposed on a silicon readout circuit substrate (12). Each microbridge (10) is supported above the substrate (12) by electrodes (14 and 16) so that a cavity (26) is present between the microbridge (10) and the substrate (12). Each microbridge (10) has a collecting area, a region of which is occupied by a ferroelectric active element (20) which converts to received thermal radiation into an electrical response. Radiation which is received by regions of the collecting area not occupied by the active element (20) is converted into heat energy and then transmitted to the active element (20) by conduction.

Abstract: An improvement for a decentered annular ring resonator (DARR) 10 for a laser whereby misalignment sensitivity to odd-periodicity azimuthal phase errors is reduced. A front and a rear waxicon reflector 18 and 20 are employed, the front waxicon 18 having four reflecting surfaces 60,62,64 and 66 and the rear two 70 and 72. The laser beam is cycled between the waxicons twice, the front waxicon 18 separating the paths of the first and second cycle beams. The rear waxicon 20 provides a 180.degree. azimuthal shift in the orientation of an incoming beam 36 so that the beam traversing the second cycle 48,50, 52 is shifted 180.degree. in azimuth relative to the beam of the first cycle 40, 42,44. Odd-periodicity azimuthal phase errors are automatically cancelled by this 180.degree. azimuthal change in orientation of the second-cycle beam 46 before it starts on the second traversal of the internal path of the DARR.

Abstract: An improvement of a common-pass, decentered, annular ring resonator (CPDARR) in which the waxicon mirror-reflector component 18 is formed with five reflecting surfaces, two on the central axicon 40, 42 and three on the outer ring axicon 44,46,48. The orientation and curvature of the reflecting surfaces is designed to provide three reflections of an input laser beam impinging on the inner reflector 40 of the central axicon and two reflections of an input wave impinging on the outer reflector surface 48 of the ring axicon (or vice versa). The number of reflections in the waxicon 18 combined with the two reflections in the rear ring mirror 20 of the CPDARR allows all reflecting surfaces to be coated with conventional high-reflectance coating and still provide a uniform-polarity output laser beam from the CPDARR.

Abstract: An optical resonator having an annular cylindrical gain region for use in a chemical laser or the like in which two ring-shaped mirrors having substantially conical reflecting surfaces are spaced apart along a common axis of revolution of the respective conical surfaces. A central conical mirror reflects incident light directed along said axis radially outwardly to the reflecting surface of a first one of the ring-shaped mirrors. The radial light rays are reflected by the first ring mirror to the second ring mirror within an annular cylindrical volume concentric with said common axis and forming a gain region. Light rays impinging on the second ring mirror are reflected to diametrically opposite points on the same conical mirror surfaces and back to the first ring mirror through the same annular cylindrical volume. The return rays are then reflected by the conical mirror surface of the first ring mirror back to the central conical mirror.