Abstract: An optical system, such as a fiber laser amplifier, including a plurality of optical sources, such as fiber amplifiers, each generating a beam. In one embodiment, the system includes first and second diffraction gratings that correct the angle of the propagation direction of the beams to remove angular dispersion caused by a diffractive optical element (DOE). In another embodiment, the system includes a single diffraction grating, where the optical beams pass through the grating twice to also remove the angular dispersion caused by the DOE.

Abstract: A solid state zig-zag slab laser amplifier in which depolarization occurring at total internal reflection from opposed lateral faces of the amplifier slab is controlled by selecting a complex evanescent coating that provides a selected phase retardance that results in minimization of depolarization. Without use of the complex coating, small changes in incidence angles can result in phase retardance changes large enough to increase depolarization significantly, especially when the amplifier is operated at higher powers. Appropriate selection of the complex evanescent coating allows a desired phase retardance angle to be maintained relatively constant over a small range of angles of incidence, at a given wavelength, and therefore permits minimization of depolarization and birefringence effects.

Abstract: A spatial light modulator having n bits of phase resolution has n stacked layers of deformable electrode pairs supporting a deformable reflective surface, each electrode pair included in upper and lower stacked elongate ribbon conductors extending in respective orthogonal directions, each coincidence of an upper and lower electrode pair defining a pixel within the respective stacked layer, each electrode pair deforming to a maximum deformation in response to an applied write voltage across the pair so as to produce at the reflective layer a phase correction of the corresponding pixel proportional to the corresponding deformation, and wherein the maximum deformation of the pixels in each stacked layer is the same, and wherein the maximum deformation of successive layers decreases in ascending order of the stacked layers.

Abstract: A relatively high average power optical laser utilizes a diode pumped multi-mode dual-clad fiber amplifier configured for double pass amplification to provide a relatively higher average power than single mode fiber amplifiers. In order to compensate for mode scrambling and depolarization from the multi-mode fiber amplifier, the output beam from the multi-mode fiber amplifier is applied to a vector phase conjugator after a single pass through the amplifier and reflected back into the amplifier. The vector phase conjugator conjugates the electric field amplitude, phase and polarization and reflects a conjugate wave back into the multi-mode fiber amplifier in a reverse direction. The propagation of the conjugate wave through the amplifier unscrambles mode mixing and restores the beam back to its original polarization state. A Faraday rotator and polarization beam splitter are used to outcouple an output beam after the second pass through the multi-mode fiber amplifier.

Abstract: The present invention relates to a laser pointing and tracking system which forms and maintains a small laser spot size at a selected aimpoint on a target and compensates for optical distortion in the intervening media. The invention comprises an illumination laser for directing a first wide divergence beam of short-pulse laser radiation toward a stationary or moving target. The target reflects a portion of the incident beam as return radiation which is interfered with a properly-timed short-pulse reference beam on an electronic radiation detector array. The detector array signals are processed to produce an electronic hologram which is imposed as a phase pattern on a spatial light modulator. A laser reads out the hologram to direct a beam of radiation at the target. Multiple sequential illumination and hologram formation/readout steps produce a small spot size at the selected aimpoint. The small spot is maintained at the aimpoint during the duration of an engagement by repeating the above steps.

Abstract: This invention concerns an apparatus and process for effectively contacting oil, catalyst, and a gas. This invention has specific applications in the design and operation of catalytic cracking units and specifically, the processing and upgrading of heavy oils to higher valued components.

Abstract: A highly efficient pumping configuration for a solid state laser uses a diode bar pumping source producing optical energy coherent along an axis normal to the plane of the diode junctions. Pump energy is nearly collimated by a cylindrical optical fiber and applied through a minimum width injection port to a low absorption solid state laser rod in a highly reflective optical cavity including a cylindrical sleeve forming a coolant chamber around the laser rod. The nearly collimated energy is focussed to a minimum width in the plane of the injection port in order to minimize the loss of energy from the optical chamber by leakage out through the port. The laser rod is substantially evenly illuminated by the entire energy entering the cavity on the first pass. Optical energy not absorbed during illumination through is reflected within the cavity until substantially absorbed by the solid state laser rod.