Abstract: A lasing apparatus includes a laser medium and a pump source. The laser medium includes one of a Holmium-doped fluoride crystal or a Holmium-doped fluorozirconate ZBLAN glass fiber. The pump source generates pulses that resonantly pump the laser medium such that the laser medium produces an output from the 5I5 level to the 5I7 level of Holmium. The pump source produces pulses having a duration that is at least as long as a storage time of the 5I5 level of the laser medium. The pump source pumps the laser medium with signals having a wavelength shorter than 1.67 ?m, with the laser medium producing an output having a wavelength of about 1.67 ?m.

Abstract: A laser apparatus is described having multiple modes of operation using intracavity optical switching within a laser resonator. The laser resonator has a solid state gain medium and one or more optical switches located between a pair of end reflectors. The pump for the gain medium has controlled duration to allow varying the pumping energy and pulse repetition rate. The laser has a Q-switched mode for generating energy from the laser resonator at a fixed level of outcoupling when the laser pump is operated to produce a range of predetermined pulse, rates and durations. The laser also has a cavity dumped mode of operation in which the laser pump is operated to produce a second range of predetermined higher pulse repetition rates and shorter pulse durations so that the pulse energy, rate and duration are selected by first Q-switching with essentially no outcoupling and then rapidly cavity dumping all the optical energy in the resonator.

Abstract: A microlaser is provided that has a microresonator and a pump source for side pumping the microresonator. The microresonator includes an active gain medium and a Q-switch that extend lengthwise between the opposed end faces of the microresonator. The pump source is therefore positioned so as to introduce pump signals into the microresonator via the side surface that is adjacent to and defined by the active gain medium. By side pumping the microresonator, the microlaser can generate a series of pulses having greater pulse energies and greater average power levels than the pulses provided by conventional microlasers. In addition, the side pumped microlaser can also generate pulses having greater pulse widths than the pulses provided by conventional microlasers of a similar size.

Abstract: A boresight alignment method is used for aligning a laser with an optical sighting system in a laser designator or the like. The method includes selecting a target formed of a flat sheet of material, such as a metal foil, supporting the selected target at the focus of a collimating telescope in the path of a laser beam of a laser and optical sighting system combination, such as in a laser designator, focusing the laser beam onto the one side of the target, and burning an aperture in the target with the laser beam. The method includes illuminating the target burned aperture from the rear thereof with a visible light or with an infrared source and then aligning the optical sighting system with the illuminated target aperture. Both the day and night viewing optics can be aligned by providing pinhole illumination with multi-spectral target pinhole illumination. The target may be mounted so that it can be rotated to provide successive alignments of the same or different laser optical sighting systems.

Abstract: A laser diode pumped laser has a laser diode wavelength sensing and control apparatus. A laser medium is mounted in a laser cavity and has a laser diode pump having a laser diode or laser diode array having an output of a predetermined wavelength for exciting the laser medium. An optical radiation detector is coupled to the output of the laser medium to receive and measure the radiation from the laser diode transmitted through the laser medium and a detector bias and signal measurement circuit is coupled to the optical radiation detector to receive signals therefrom and generate an output signal responsive to the optical radiation detector signals and to apply the generated signals to the laser diode power supply (or to diode heaters) to vary the power supply output to vary the laser diode wavelength to maintain the laser diode wavelength at the absorption peak of the laser medium.

Abstract: A method and apparatus for testing materials for use in a laser resonator includes selecting a test fixture apparatus having a housing with an internal chamber volume selected to approximate the internal volume of a predetermined laser resonator and having a pair of sealed windows therein which are removably attached to the housing and having optical coatings selected to match the coating on the optics of a laser. The housing has a removable cover and a gas purging opening. A laser of a predetermined wavelength and power is mounted adjacent the test fixture and is aligned for directing the laser beam through both of the windows of the test fixture. A material is placed in the test fixture and a laser beam directed through the coated windows for a predetermined period of time and thereafter the coated windows are examined for damage or contamination. The test fixtures are also cleaned and certified prior to testing so that a preselected test fixture can determine damage for selective materials used therein.

Abstract: A decontaminate apparatus for a laser system includes a laser having a compartment housing having a base and walls formed into a cavity and having a compartment cover having at least a portion thereof porous to predetermined gases used in laser system optical cavities. The compartment housing cavity is filled with a selected decontaminating material held therein by the porous cover and is attached in the laser system housing so that selected contamination in the laser system optical compartment gas is absorbed by the selected material in the compartment. The compartment cover can be made of a porous silica.

Abstract: The efficiency of an optically pumped solid state laser is substantially improved with a controlled geometry fluorescent converter between the pump light source and the lasing medium. Fluorescent materials have the capability of absorbing broadband pumping radiation, shifting it in wavelength and re-emitting it in the absorption band of the selected solid state laser medium. Use of angular formations having the converter surface facing the laser medium reduces fluorescent light trapping within the converter due to internal reflection thereby greatly increasing the total light output of the converter and thus the efficiency of the laser.

Abstract: An adjustable optical mounting assembly, particularly suited for folding or periscope optics, provides for optical beam motion in three axes using a bearing having a spherical surface. This invention greatly simplifies the mount mechanism and operting procedure, reduces the size, and provides enhanced stability and lockability relative to comparable conventional devices.

Abstract: The output of a laser oscillator is doubly passed through a birefringement medium, a quarter-wave plate and a laser amplifier by reflection from a phase conjugate mirror, the birefringent medium being between the oscillator and the plate in the path of the initial and reflected oscillator output. The birefringent medium divides the oscillator output into a first set of orthogonal polarization components (rays) and refracts one of them at a first angle successively through the plate and amplifier for reflection from the mirror through the amplifier, plate and medium. The reflected ray is amplified and then divided by the medium into a second set of orthogonal ray components which exit the medium at different angles away from the oscillator. In another embodiment, a second quarter-wave plate is added between the amplifier and mirror, and in a third embodiment the amplifier is positioned between the oscillator and the birefringent medium.

Abstract: The exterior surfaces of a laser rod and pump lamp are covered with a highly reflective metal foil to prevent light leakage from the rod and lamp. The laser rod and pump lamp operate within a cavity inside a heat sink. Between the metal foil and the housing is a thermally conductive fluidic material selected to provide a tailored thermal impedance between the heat sink and the rod and pump to optimize the steady state temperatures of these components. The conductive fluid is not circulated but is contained to act as a simple heat conductor. The optically reflective and the heat transfer functions of the laser pumping operation are essentially separate from each other, enabling selection of materials for these respective functions to enhance performance of the laser and substantially simplify its construction.

Abstract: The exterior surfaces of a laser rod and pump lamp are covered with a highly reflective metal foil to prevent light leakage from the rod and lamp. The laser rod and pump lamp operate within a cavity inside a heat sink. Between the metal foil and the housing is a thermally conductive fluidic material selected to provide a tailored thermal impedance between the heat sink and the rod and pump to optimize the steady state temperatures of these components. The conductive fluid is not circulated but is contained to act as a simple heat conductor. The optically reflective and the heat transfer functions of the laser pumping operation are essentially separate from each other, enabling selection of materials for these respective functions to enhance performance of the laser and substantially simplify its construction.

Abstract: Laser apparatus having a very narrow (<1A) spectral output comprises a laser cavity having a metal vapor cell as one of the reflecting elements. This cell reflects the laser beam over a narrow wavelength region in the vicinity of one of the metal vapor's resonant absorption lines and achieves frequency locking to an atomic resonance line without any external frequency sensors or feedback loops.

Abstract: A pulsed or CW laser is rapidly switched to operate at one or more selectable wavelengths by means of intracavity insertion of beam dispersion and focussing elements and an apertured focal plane mask and shutter assembly. The laser beam has an axis and is dispersed into components or sub-beams having different axes and representing different wavelengths, the sub-beams being focussed to substantially reduced diameters on the focal plane mask at points, respectively, at which apertures are formed. Movable shutters adjacent to the respective apertures control alternate opening of and closing of the apertures and selectively permit the laser to resonate at at least one of a plurality of wavelengths corresponding to that of the sub-beam passing through an open aperture. Mask apertures having very small diameters (<50 microns) and separations are achieved enabling switching between different operating wavelengths in milliseconds.

Abstract: A conduction cooled solid state laser comprises a laser rod and a pump lamp within a pump cavity in a housing constituting a heat sink, the remote exterior surfaces of the rod and lamp being covered by highly reflective metal foils in intimate contact with those surfaces and backed by a thermally conductive material between the foil and housing that is selected to provide a tailored thermal impedance. The foil acts as a highly efficient reflector and as a thermal contact element between the heat source (rod or lamp) and backing material, the latter, in either solid or fluid form, being selected to provide the desired thermal impedance between the source and sink to optimize component temperatures. The optically reflective and the heat transfer functions of the pumping operation are essentially separate from each other, enabling selection of materials for these respective functions to enhance performance of the laser and substantially simplify its construction.

Abstract: A laser electrode assembly comprises an elongated bar having a plurality of longitudinally spaced sockets and is removably secured to a carrier which is anchored to the laser base and has a like number of plugs resiliently press-fitted within the sockets, respectively. Each plug has opposed sides to which are fastened a plurality of outwardly curved resilient fingers extending parallel to the direction of insertion of the plugs into the sockets. Each socket has a width less than the overall width of the plug and finger combination so that the fingers resiliently frictionally engage the bar within each socket. The bar is readily removed from the carrier for maintenance and repair purposes by prying the former from the plugs without necessitating removal of screws or bolts and thereafter passing the bar through the window opening aligned with the discharge gap.

Abstract: A dye laser is disclosed wherein a plastic disk containing laser dye is moved within a cylindrical race relative to a stationary pumping laser beam such that the pumping beam effectively scans the surface of the laser disk along a cycloidal path as the disk rolls along the race surface. The cycloidal illumination pattern on the disk enables a significantly increased amount of laser material to be exposed to the pumping beam.