Abstract: An optical communications terminal including a polarizing element responsive to a first linearly polarized optical beam and rotating the first linearly polarized optical beam in a first linear direction, a beam separator responsive to and passing the first linearly polarized optical beam, and a circular polarizing element responsive to the first linearly polarized optical beam from the beam separator and circularly polarizing the first linearly polarized optical beam for transmission, where the circular polarizing element is switchable between two orthogonal switching states. The terminal receives a circularly polarized optical beam from another terminal and linearly polarizes the circularly polarized optical beam from the other terminal in a second linear direction that is orthogonal to the first linear direction and the beam separator directs the circularly polarized optical beam from the other terminal in a direction away from the polarizing element.

Abstract: An optical communications terminal including a polarizing element responsive to a first linearly polarized optical beam and rotating the first linearly polarized optical beam in a first linear direction, a beam separator responsive to and passing the first linearly polarized optical beam, and a circular polarizing element responsive to the first linearly polarized optical beam from the beam separator and circularly polarizing the first linearly polarized optical beam for transmission, where the circular polarizing element is switchable between two orthogonal switching states. The terminal receives a circularly polarized optical beam from another terminal and linearly polarizes the circularly polarized optical beam from the other terminal in a second linear direction that is orthogonal to the first linear direction and the beam separator directs the circularly polarized optical beam from the other terminal in a direction away from the polarizing element.

Abstract: An optical communications system including two communications terminals in communication with each other using optical signals having the same wavelength. Both terminals include a half-wave plate polarizer for rotating linearly polarized optical signals and a quarter-wave plate polarizer for circularly polarizing the optical signals. The quarter-wave plate polarizers are oriented 90° relative to each other so that circularly polarized optical signals sent from one terminal to the other terminal are linearly polarized 90° relative to a transmission polarization orientation to be separable from the transmitted optical signals by a beam splitter.

Abstract: An optical communications system including two communications terminals in communication with each other using optical signals having the same wavelength. Both terminals include a half-wave plate polarizer for rotating linearly polarized optical signals and a quarter-wave plate polarizer for circularly polarizing the optical signals. The quarter-wave plate polarizers are oriented 90° relative to each other so that circularly polarized optical signals sent from one terminal to the other terminal are linearly polarized 90° relative to a transmission polarization orientation to be separable from the transmitted optical signals by a beam splitter.

Abstract: An exemplary support structure for a planar faceplate includes ribs extending substantially perpendicular to a bottom surface of the planar faceplate. Spaced apart projections extend from the ribs towards the bottom surface of the planar faceplate and have distal ends that engage and are secured to the bottom surface. Each distal end defines an area with a numerical value that is less than the thickness of the planar faceplate measured in the same measurement units as the area to limit any stress formations induced in the planar faceplate due to thermal changes from reaching a top surface of the planar faceplate. Alternatively, the projections may be spaced apart mesas extending outward from a rigid material.

Abstract: An exemplary support structure for a planar faceplate includes ribs extending substantially perpendicular to a bottom surface of the planar faceplate. Spaced apart projections extend from the ribs towards the bottom surface of the planar faceplate and have distal ends that engage and are secured to the bottom surface. Each distal end defines an area with a numerical value that is less than the thickness of the planar faceplate measured in the same measurement units as the area to limit any stress formations induced in the planar faceplate due to thermal changes from reaching a top surface of the planar faceplate. Alternatively, the projections may be spaced apart mesas extending outward from a rigid material.

Abstract: An optical bench 10 is cast from a single piece of material and provided with a number of optical component supports 14 which extend upwardly from a base 12. The optical component supports 14 are integral with the base 12, increasing their rigidity. The bench 10 may be cast with additional material in strategic areas to allow for future optimization of the bench 10—for example, the mounting of specific optical components throughout the bench 10. Further, the bench 10 may be provided with regions 24, 26, and 28 of varying rigidity by placing support struts 68 closer together in areas where greater rigidity is required. Apertures 30 may be provided in the bench 10 to enable the routing of conduits through the bench 10.

Abstract: An array of cylindrical end-caps with separate or integral lenses is stacked with its members in close contact, forming inter-cylinder gaps between every subset of three adjacent cylindrical lenses. Conductive fibers are disposed in the inter-cylinder gaps. Heat that would otherwise accumulate in the array is removed through the conductive fibers and transmitted to an external heat sink.

Abstract: A compact fiber packaging system for fiber lasers is provided that comprises a series of spools nested inside one another for efficient volume utilization. The spools comprise an inner spool nested inside at least one outer spool to form a module. Generally, the fiber lasers are wrapped around the inner spool, and then around successive outer spools as required to form the module. Furthermore, the modules may be stacked to form a fiber assembly. The compact fiber packaging system further comprises devices and methods for minimizing thermal gradients between fibers and for removing Waste heat from the system. Additionally, the available volume is further utilized by disposing equipment and materials for operation of the fibers inside a hollow center defined by the inner spool, between the nested spools, and adjacent the nested spools.

Abstract: A compact fiber packaging system for fiber lasers is provided that comprises a series of spools nested inside one another for efficient volume utilization. The spools comprise an inner spool nested inside at least one outer spool to form a module. Generally, the fiber lasers are wrapped around the inner spool, and then around successive outer spools as required to form the module. Furthermore, the modules may be stacked to form a fiber assembly. The compact fiber packaging system further comprises devices and methods for minimizing thermal gradients between fibers and for removing Waste heat from the system. Additionally, the available volume is further utilized by disposing equipment and materials for operation of the fibers inside a hollow center defined by the inner spool, between the nested spools, and adjacent the nested spools.

Abstract: A submarine antenna assembly comprises a tubular body having a removable end cap, a mast stowable in the body and extendible therefrom and having elements mounted thereon, a penetrator stowable in the body and movable therefrom by the mast upon removal of the end cap, the penetrator being adapted to bore through an ice layer, and an inflatable ring stowable in the body and movable therefrom by the mast upon the removal of the end cap. First and second capsules are in the body for retaining and releasing gas, the first capsule being adapted upon opening thereof to pressurize the body to blow off the end cap to permit movement of the mast, the ring, and penetrator out of body, and the second capsule being adapted to inflate the ring to hold the penetrator in engagement with an undersurface of the ice layer. An electronics assembly is disposed in the body and includes message retention and transmitting means in communication with the mast, and timer means in communication with the capsules.

Abstract: The laser beam produced by the improved precision laser maintains an axial stability of less than 20 micro-radians in the presence of ambient temperature changes and shock and vibration of as much as 100 g's, achieving a new milestone in stability. In the new laser one end of the resonator (7) is hard mounted to the laser bench (13) and the other end of the resonator is mounted to that laser bench by a flexure (17). The flexure is designed to resiliently yield in the presence of thermally induced strain on the bench while retaining sufficient stiffness against foreseeable shock and vibration.

Abstract: A solid state laser apparatus 10 including a laser gain module 12 for generating high energy laser beams 50 and 52 accompanied by non-lasing radiation 60 which, generates heat in the environment of the laser gain module and the apparatus, generally having an adverse affect on the performance of the apparatus. A heat shield 14 encloses the laser gain module to absorb the non-lasing radiation 60 to shield the components surrounding the shield against temperature increases above levels that adversely affect the laser performance and shields the reflective units 20 and 22. Affixed to the heat shield 14 is a cooling pipe 66 which provides coolant to the roof 64 of the heat shield 14 removing the heat that is absorbed. The pipe 66 is connected to a heat exchanger and pump 24 that circulates coolant through the piping. The heat shield 14 and the cooling apparatus 66 and 24 are designed to keep the temperature increases within 20.degree. C. of the nominal base operating temperature for a particular system.

Abstract: A beam monitoring assembly (10) that provides near-field imaging, far-field imaging and power measurements of a laser beam (12) in real-time for alignment and performance verification purposes. The monitoring assembly (10) includes a holographic beam splitter (24) that splits the laser beam (12) from the laser resonator cavity into a series of separate split beams (28, 30, 32) having varying beam powers. One of the split beams (28) is directed to a power meter (36) to measure the power of the beam (12). One of the split beams (28) is directed to a near-field camera (42) that provides a near-field image of the beam (12). Another one of the split beams (30) is directed to a heat dump (52) that absorbs and removes the beam's energy from the assembly. Another one of the split beams (32) is directed to a far-field lens (46) that focuses the split beam (32) onto a far-field camera (50) that provides a far-field image of the beam (12).

Abstract: A detector 50 is included in a laser apparatus for generating a high energy laser beam to protect against the uncontrolled escape of the high energy laser beam from its prescribed optical path 14. The high energy laser beam proceeds along the optical path 14 and is directed to a work site 44 by a series of reflective surfaces in its path 26 and 30. The series of reflective surfaces function to change the path 14 of the beam 32 from the generating source to the work station 44. Associated with each of the reflective surfaces is a detector 50 which comprises a conductive frame 51 having a front face 52 and a back face 54. The back face 54 is equipped with a thermal sensor 60 which is positioned in a base portion 64 of the heat conductive frame 51. The detector is equipped with cooling means 58 and 66 for maintaining the threshold temperature.

Abstract: A polarizer/modulator assembly (10) including a polarizing unit (12) and a modulator unit (14) that are selectively and independently positionable within a resonator cavity of a solid state diode slab laser. The polarizing unit (12) includes a pair of polarizing elements (32, 34) positioned in a "V-shaped" configuration so that both elements (32, 34) are positioned at Brewster's angle with respect to the beam path to combine to polarize the light in the same direction. The combination of the polarizing elements (32, 34) eliminates beam deflection when the polarizer unit (12) is inserted into the beam path. The polarizing elements (32, 34) are mounted in a metal housing (30) that captures rejected light from the polarizing elements (32, 34). The housing (30) includes a cooling tube (52) to control temperature of the housing (30) during temperature build-up caused by the rejected light.

Abstract: There is provided an optically pumped laser apparatus 10 which includes a heat conductive assembly 14 which is affixed to a solidstate yag laser crystal medium for generating a laser beam 49 within the laser crystal medium 12. The heat conductive assembly 14 comprises a heat diffusing element 32 which serves to diffuse the heat that is generated through the cooling surfaces 24 and 26. It includes a heat discharging structure 33 for removing the heat from the system. The efficiency of the laser system is improved by the geometry of pumping the crystal laser medium along the paths shown by the arrow 40 and to directing heat removed by the heat conductive assembly along the arrows 42, which paths are normal to one another and which provide an effective geometry that minimizes temperature variations within the laser crystal 12 to provide a low value for the OPD of the system.

Abstract: An optical amplifier for a high power, solid state laser which includes a slab of a solid state laser material, for example, yttrium-aluminum-garnet (YAG) crystal. One or more diode arrays may be vertically stacked and configured to provide generally uniform energy distribution in the crystal in a vertical direction. By maintaining a relatively uniform energy distribution in the crystal in a vertical direction, thermal and stress aberrations of the resulting laser beam are minimized.

Abstract: An optic cell 20 for use in the cavity of a high-power laser comprises an optic housing 22 which defines a first laser beam aperture 26. An optic element 32 such as a mirror or lens is disposed within the optic housing. A first indium layer 30 is between and in abutting contact with the optic housing and the optic element. An optic cover 40 defines a second laser beam aperture 46 therethrough substantially in alignment with the first laser beam aperture to form a window 47 of the optic element through which a laser beam passes. A second indium layer 48 is between and in abutting contact with the optic element and the optic cover. The optic housing and the optic cover are typically formed of aluminum or copper to passively cool the optic element.

Abstract: A compact diode pumped solid state slab laser gain module 20 is described. The laser gain module comprises a ceramic housing 22, a laser gain medium 24 disposed in the laser cavity 22, and an optical pumping source. The housing is preferably composed of alumina which provides thermal and structural stability at high temperatures to maintain beam alignment and eliminates parasitic oscillations. The laser gain medium is preferably a slab of crystalline Nd:YAG. Diode laser arrays 48, 50 are provided to pump at least one side face 30, 32 of the laser gain medium. Each diode laser array 48, 50 is mounted to a manifold 40, 42 preferably formed of a plastic, non-contaminating material. The laser gain module comprises a simplified cooling distribution for cooling the laser gain medium to produce a substantially uniform temperature distribution between its top and bottom faces, and for cooling the diode laser arrays.