Abstract: A Coupled Multiple Output Resonator (CMOR) having two symmetric modules 10,20, is created by adding self-feedback (SFB) mirrors 104,106 aligned with apertures 100,102, in output scraper mirrors 14,24, respectively, to a conventional Multiple Output Resonator (MOR). The SFB mirrors re-inject a portion of the output beams 34,42 back into the resonator cavity as adjoint beams 108,110 which alter the modes of the system such that the CMOR only lases at desired modes where all the output beams 34,42 are in-phase. The CMOR provides substantially constant acceptable mode discrimination for more than 4 modules with only one SFB mirror per module and no additional external coupling paths between modules, thereby allowing the system to be scaled to any number of lasers without reduction of target intensity. Also, the SFB mirrors are small and are easily controlled to compensate for cavity mirror variations to maintain the desired mode discrimination.

Abstract: An improved ring laser system having mutual coupling between two or more ring laser resonators employs a two-step coupling process, in which coupling power is coupled into the adjoint forward mode of an adjacent resonator, from which it diffractively couples to the forward mode. A portion of forward-mode power is coupled into the adjoint reverse mode from which it diffractively couples to the reverse mode within each resonator. A portion of this reverse mode power is used to coupled into other resonators. A complementary configuration employs forward-mode radiation as the coupling radiation.

Abstract: An array of unstable laser resonators has a set of coupling beam paths, each of which carries coupling radiation to and from output regions of a pair of resonators in the array, so that pairs of resonators are symmetrically coupled to one other.

Abstract: A resonator is disclosed having a mode control cavity and a power extraction cavity capable of being independently optimized to produce a laser beam having high power and good optical quality in the far field. The mode control cavity is a positive branch confocal unstable resonator having large geometric magnification and a low Fresnel number to provide mode discrimination against higher order radial and azimuthal modes such that the lowest loss mode, typically the lowest order fundamental mode is strongly favored. The power extraction cavity is adapted to accommodate a gain medium having a large volume. A first cone adapted to provide line of sight communication between the mode control cavity and the power extraction cavity optically couples the cavities and provides means for varying the diameter of radiation passing between the mode control cavity and the power extraction cavity.

Abstract: A variable output resonator is disclosed having a mode control cavity and a power extraction cavity both capable of being independently optimized to produce a laser beam having high power and good optical quality in the far field. A cone having a conical reflective surface is adapted to be linearly moved along a beam axis of the power extraction cavity in the resonator to intercept a portion of the radiation circulating therein to produce the laser beam. Both the diameter and power level of the laser beam are dependent upon the area of the reflective surface of the cone which interacts with the radiation circulating within the resonator. The insertion of the cone into the resonator does not influence the overall resonator alignment since the cone is external to the optical components defining the resonator.

Abstract: A stable resonator is disclosed capable of providing a laser beam having both high power and good optical quality from a large volume gain medium. The stable resonator is formed having an optical cavity defined at one end by an unstable resonator and at the other end by a reflector in optical communication with the unstable resonator.