Abstract: An improved optically pumped, acousto-optically Q-switched laser is disclosed, capable of significantly increased output energy. Optical coatings, with their inherent limitations on maximum energy of the output pulse, are completely eliminated. At the reflecting surfaces, Porro prisms replace the mirrors conventionally used. At the non-reflecting or transmitting surfaces, conventional, anti-reflective coatings are eliminated by placing the respective elements at the Brewster angle for the dominant polarization of the Q-switching material. Optimum output coupling is achieved by adjustment of the Q-switch drive. In order to prevent undesired second pulses in the output, which normally limit the maximum attainable output energy, a filtering shield of material opaque to the operating frequency is placed in the laser cavity, between the flash pump and the laser rod, to minimize the possibility of a second-pulse buildup due to random emission before the Q-switch is turned fully off.

Abstract: Working gas for an electron beam discharge laser is generated by an airbreathing, hydrocarbon fuel burning, turbocompressor engine and shaft power of the engine may be utilized to drive a generator to provide electric power to the laser or to drive a compressor to put the turbocompressor exhaust gases in compressed storage for later use in the laser, either mode affording savings in weight and cost of operating materials and/or specific energy conversion efficiency compared to prior art, electric, chemical and gas dynamic laser systems.

Abstract: A laser discharge tube assembly is disclosed, such assembly including a pair of blocks, one having an optically flat surface and the other having at least a pair of grooves formed in an optically smooth surface thereof, the surfaces of the pair of blocks being fixed in mutual contact when assembled to form a laser capillary. With such arrangement various folded capillaries, such as V-shaped or W-shaped capillaries, may be easily and accurately fabricated. Laser discharge tubes, each having a folded capillary, are disclosed in a ring laser gyroscope application to increase the length of the capillary in a given area, thereby maximizing the gain of the laser resonator used in such application.

Abstract: A buried-heterostructure (BH) diode injection laser capable of operating at low room temperature thresholds and in the lowest order TE, TM or TEM modes. The laser has an elongated groove in a substrate with the groove extending through a pump current confining layer with a central portion of the active layer substantially completely within the groove and substantially completely surrounded by light guiding and carrier confining layers of material having a lower index of refraction than the index of refraction of the material of the active layer. The light guiding and carrier confining layer in contact with the substrate has a central depression within the elongated groove and the central portion of the active layer is bowl-shaped and within the depression such that light waves produced by carrier recombination within the central portion of the active layer when the laser is forward biased are guided in the central portion of the active layer such that the laser produces a light beam having reduced width v.

Abstract: The members which are utilized to hold and position a rod of erbium laser glass material within an imaging cavity are formed of a glass material which is transparent at the pumping wavelengths of the erbium ions and/or associated sensitizer ions in order to prevent masking of the laser rod to the pumping light energy at those locations where the holders come into contact with the laser rod. This arrangement optimizes the performance of the erbium glass laser rod configuration.

Abstract: The metal end plates of a laser device are provided with relatively large annular hub portions extending outwardly from the laser envelope. Glass mirror blocks are used, each having a small area of a reflective coating in the center of one surface of the block. To bond the block to an end plate of the laser device, the mirror is aligned substantially on the axis of the hub and rf energy is used to heat the end of the hub to a sufficiently high temperature to seal it to the glass. The hub is brought into contact with the glass surface of the mirror block and a seal is made without damage to the mirror coating.

Abstract: An electrochromic display for selectively displaying optical patterns comprising a sandwich type structure which includes transparent front electrodes, electrochromic layers on the front electrodes, an electrolyte and a special electroreactive layer on a rear electrode. The electroreactive layer, which serves as hydrogen source, is composed of electrochemical material which is first oxidized and subsequently heat treated in a hydrogen or forming gas atmosphere to improve the operating and life characteristics of the display. The electrodes are mounted or deposited respectively on parallel substrates which form the outer structures of a hermetically sealed display arrangement. The electroreactive layer can be a single layer structure serving the functions of both the rear electrode and hydrogen source material.

Abstract: An improved self Q-switching Nd--UO.sub.2 -glass laser is provided in which a diffusing medium is included, either within the laser rod or externally thereof to increase the effective volume of the laser rod. Various diffusing means are disclosed including optical inhomogeneities, diffusion coatings, and curvilinear resonators.

Abstract: An electrochromic data display and imaging device which may be formed by sandwich arrangement of the imaging area, the counter-electrode area with a suitable electrolyte layer between, the imaging area and/or counter-electrode area having greater uniformity of charge.

Abstract: The present invention relates to improved method and structure for producing an electric discharge in a laser cavity which eliminates arcing and permits electron energy to be chosen based on energy requirements for accelerating the electrons rather than energy and/or pressure requirements for supplying electrons. An auxiliary discharge is maintained to provide the electrons necessary for laser excitation. A transverse electric field is then superimposed to impart the energy required to accelerate the electrons.

Abstract: A gas laser emits an output laser beam from a low pressure region to a region having a higher pressure. This is done through an opening in the side of a laser device. Under normal circumstances, the provision of such an opening would incur a flow of air from the high pressure side, externally of the laser device, to the low pressure side within the device. To prevent this, an aerodynamic window is placed in a passageway leading from said opening in the laser device through which the laser beam passes. A gas flow is passed across said passageway which will provide a flow which represents the flow of a segment of a free-vortex flow field having a pressure differential across the segment which is equal to that between the low and high pressure regions. A single nozzle, specifically contoured to produce a segment of a free-vortex flow field directs the gas into the passageway and an opening collects the flow onto the other side of said passageway. A method of constructing such a nozzle is set forth.

Abstract: A gas laser emits an output laser beam from a low pressure region to a region having a higher pressure. This is done through an opening in the side of a laser device. Under normal circumstances, the provision of such an opening would incur a flow of air from the high pressure side, externally of the laser device, to the low pressure side within the device. To prevent this, an aerodynamic window is placed in a passageway leading from said opening in the laser device through which the laser beam passes. A gas flow is passed across said passageway which will provide a flow segment having a pressure differential across the segment which is equal to that between the low and high pressure regions. When such an aerodynamic window is used in an aircraft and the aircraft experiences changes in altitude, the pressure differential across the flow segment changes.

Abstract: A gas dynamic-transfer chemical laser is formed by burning a halogenated and deuterated tetrazole and expanding the combustion products through a supersonic nozzle and injecting into the expanding products, a secondary stream of cold D.sub.2 or cold H.sub.2.

Abstract: A high power, cw, high pressure, electrically excited flowing gas laser is disclosed wherein a laser excitation transverse to the direction of gas flow is initiated by a uniform electron beam perpendicular to the gas flow direction. Laser gas supplied to a plenum chamber at a pressure substantially greater than atmospheric pressure is conditioned by a perforated plate nozzle to flow through the laser cavity in a uniform stream at the desired subsonic velocity. A variable angle diffuser is provided downstream from the laser cavity to decelerate and compress the laser gas before exhausting it into the ambient atmosphere such that at the downstream end of the laser excitation region the laser gas is maintained at a pressure slightly lower than atmospheric pressure.

Abstract: A new class of high-power lasers capable of high efficiencies in the visible and shorter wave lengths is taught, employing an excitation energy transfer mechanism from a pumped noble donor gas, such as Argon, to an acceptor lasing gas, preferably Nitrogen. In particular, such an Argon/Nitrogen laser exhibits a very useful, unique output wave length at 3577A, this being derived from a mixture of Argon, predominantly, with a minor percentage of Nitrogen, excited by a relativistic electron beam of relatively high current density. Such gas lasers with a noble gas as donor offer great promise, using high electrical conversion. efficiency of the noble donor gas with a non-radiative energy transfer to the lasing gas.

Abstract: A gas laser including a discharge tube containing a gas mixture, the discharge tube having one or more inlets and an outlet, in which a reaction vessel is in communication with said outlet and with the inlet of a vacuum pump, and in which the outlet of the vacuum pump is in communication with the or each inlet of the discharge tube.

Abstract: An improved transverse-discharge gas laser tube is provided by positioning thermionic cathodes diametrically opposite each other across the plasma location with anodes positioned at 90.degree. to the cathodes all contained within an electron repelling envelope. Laser configurations for both large and small circular cross-section plasmas are disclosed. A thermionic cathode plasma slab laser with a magnetic field that may be modulated to provide modulation of the laser beam is also disclosed.

Abstract: The laser comprises an amplifying medium which sustains the oscillation within two resonators, one resonator being formed by the mirrors M.sub.1 and M'.sub.1 and the other being formed by the mirrors M.sub.2 and M'.sub.2. The quality factor of the second resonator is higher than that of the first resonator. The time-duration of the pulse extracted from the first resonator is adjusted by modifying the quality factor of the second resonator.The double-resonator laser serves to generate pulses of very small width, especially in dye lasers, and to adjust pulse-widths in such applications as telemetry.

Abstract: Method and apparatus for providing a large fraction of the energy coupling from an unstable resonator in the central lobe of the far field pattern of the output beam from the resonator are disclosed. The resonator is designed to allow a low order mode pattern to resonate about the optical axis therethrough and radiation is coupled out from both the axial region and the outer region of the mode. The geometry of the systems is formed with transmissive and reflective optics in various configurations of linear and ring lasers.

Abstract: In a liquid crystal display device the homogeneous alignment of twisted nematic liquid crystal molecules is accomplished by providing a first thin dielectric layer on the inner surfaces of each of the spaced apart glass plates covering complementary patterns of transparent electrode material. Applied to the dielectric layer on each plate is a second thin film of aligning material such as silicon monoxide. The first dielectric layer provides maximum isolation to the liquid crystal material and a uniform layer for subsequent application of the aligning film.