Abstract: A system employing a solid state light source for writing Bragg gratings in fibers and for other photolithographic applications. The solid state light source preferably has a passively Q-switched laser, a fiber amplifier and two or more nonlinear conversion elements for delivering a pulsed exposure beam at an exposure wavelength in the UV wavelength range. The exposure beam is generated in a single pass through the nonlinear elements, for example by cascaded second harmonic generation yielding the fourth harmonic. The system is effective at covering the UV wavelengths from 200 nm to 330 nm and particularly effective at producing an exposure wavelength between 240 and 250 nm at average power levels of 500 milliWatts and more within a photosensitive range of fiber cores in which Bragg gratings are to be written.

Abstract: A Thulium-doped silica fiber normally has its strongest gain at 1.9 microns and thus is not suitable for communication use. By engineering a W-profile or depressed cladding fiber with an appropriate index profile having a fundamental mode cut-off between 1.9 microns and the shorter wavelength of desired operation, an optical amplifier based on the W-profile Thulium-doped silica fiber operates at wavelengths shorter than conventional amplifiers, just above what is currently called the Erbium L-band. In a preferred embodiment, the cut-off wavelength is at or near 1.7 &mgr;m, eliminating longer wavelengths from the fiber. Amplifiers engineered according to the principles and techniques of the present invention can operate in the wavelength range between about 1.6 to 1.8 microns, which is particularly useful for telecommunications.

Abstract: Methods and apparatus for controlling a passively Q-switched laser (PQSL) that use a Q-switched laser as a voltage controlled oscillator (VCO) in a phase-locked loop control circuit are disclosed. The PQSL may be optically coupled to a detector. The detector may be coupled to a an input of a phase lock loop controller. A reference oscillator may be coupled to a reference input of the phase lock loop controller. An output of the phase lock loop controller may be coupled to an integrator. The integrator may be coupled to a means for controlling an amount of power provided to the PQSL.

Abstract: An approach to blue light in a single, integrated system is disclosed. An oscillator generates source radiation at a wavelength near 0.91 microns and a few milliwatts of power. This power is amplified to multi-Watt levels in a Neodymium-doped cladding-pumped fiber device that has its gain suppressed at 1.05 microns. A harmonic generator frequency-doubles the output of the fiber device to produce radiation at a blue wavelength near 0.455 microns. Mirrors, gratings or other means in the fiber expel wavelengths of light at or near 1.05 microns while allowing 0.91 micron radiation to remain in the fiber. Gain at 1.05 microns may alternatively be suppressed by adjusting the refractive index profile of the fiber to eliminate bound-modes at 1.05 microns or by bending the fiber to attenuate radiation at 1.05 microns. The laser may include a high brightness pump to enhance the transition that produces 0.91 micron radiation.

Abstract: An apparatus and a method for separating a light of a first wavelength &lgr;1 from a second wavelength &lgr;2, where &lgr;1<&lgr;2, in a waveguide such as an optical fiber is described. The apparatus includes a core surrounded by a depressed cladding, which itself is surrounded by a secondary cladding. The core cross-section, the depressed cladding cross-section, the secondary cladding cross-section, and the refractive indices of the core, the depressed cladding and the secondary cladding are selected to produce a fundamental mode cutoff wavelength &lgr;c such that &lgr;1&lgr;c<&lgr;2, and produce a high loss at the secondary wavelength &lgr;2. The apparatus can be used as a filter, an amplifier, a laser, or in a nonlinear optical switch.

Abstract: A light source employing a passively Q-switched laser, a fiber amplifier and a nonlinear element for performing single pass frequency conversion to generate a pulsed output beam. The Q-switched laser delivers a pulsed primary beam at a primary wavelength which is amplified by fiber amplifier to produce a pulsed intermediate beam containing pulses at the primary wavelength. The Q-switched laser is configured such that these pulses have a certain format. Specifically, these pulses have a format corresponding to a certain frequency conversion efficiency, preferably higher than 10% or even higher than about 50% in single pass frequency conversion performed by the nonlinear element. The nonlinear element includes one or more nonlinear crystals for performing a single or cascaded nonlinear conversion operations. Depending on the application of the light source, the primary wavelength range can be chosen between 860 nm and 1100 nm and the output wavelength can range from 430 nm to 550 nm.

Abstract: A system and method for using pulses of laser light delivered in a non-overlapping sequence of first pulses at a green wavelength, second pulses at a blue wavelength and semi-continuous pulses at a red wavelength to illuminate a color generation unit for generating a color. Typically, the color generating unit is an image generating unit for producing color images and is equipped with transmissive or reflective pixels which are adjusted to select portions of the laser light generated at the green, blue and red wavelengths to obtain a desired output color. The first and second pulses preferably have a narrow pulse width and an interpulse separation equal to at least 100 times the narrow pulse width, while the semi-continuous pulses at the red wavelength have a wide pulse width equal to at least 100 times the narrow pulse width.

Abstract: A system employing a solid state light source for writing Bragg gratings in fibers and for other photolithographic applications. The solid state light source preferably has a passively Q-switched laser, a fiber amplifier and two or more nonlinear conversion elements for delivering a pulsed exposure beam at an exposure wavelength in the UV wavelength range. The exposure beam is generated in a single pass through the nonlinear elements, for example by cascaded second harmonic generation yielding the fourth harmonic. The system is effective at covering the UV wavelengths from 200 nm to 330 nm and particularly effective at producing an exposure wavelength between 240 and 250 nm at average power levels of 500 milliWatts and more within a photosensitive range of fiber cores in which Bragg gratings are to be written.

Abstract: An apparatus and a method for separating a light of a first wavelength &lgr;1 from a second wavelength &lgr;2, where &lgr;1<&lgr;2, in a waveguide such as an optical fiber is described. The apparatus includes a core surrounded by a depressed cladding, which itself is surrounded by a secondary cladding. The core cross-section, the depressed cladding cross-section, the secondary cladding cross-section, and the refractive indices of the core, the depressed cladding and the secondary cladding are selected to produce a fundamental mode cutoff wavelength &lgr;c such that &lgr;1&lgr;c<&lgr;2, and produce a high loss at the secondary wavelength &lgr;2. The apparatus can be used as a filter, an amplifier, a laser, or in a nonlinear optical switch.

Abstract: A stabilized solid-state laser in a thermal imaging system in which a laser diode pumps the solid-state laser and a modulator modulates the laser beam according to graphical data to be recorded in a thermally sensitive medium, as is used in the graphics industry. The solid-state laser is stabilized against relaxation oscillations induced in the laser by modulated light reflected back from the thermally sensitive medium. The light reflected from the medium is allowed to reenter the solid-state laser, but the optical output of the solid-state laser is sampled in the frequency band in which relaxation oscillations occur. The detected intensity is then used in a feedback circuit to control the intensity of the diode laser that is optically pumping the solid-state laser. Thereby, the data modulation does not cause the solid-state laser to oscillate, and neither a Faraday rotator nor use of a diffracted beam is required.

Abstract: A method and apparatus for applying a lubricant to an object is disclosed. The lubrication apparatus includes a rotatable and cylindrically shaped brush for applying the lubricant to the object, a housing for holding the brush, and a pump for applying the lubricant to the brush located in a chamber positioned below the brush. A vertical slide cylinder moves the brush in a generally vertical direction along the central axis in and out of the chamber, and a horizontal slide cylinder moves the brush in a generally horizontal direction transverse to the central axis to contact the object. The chamber has a sloped chamber cap connected to the top portion of the chamber for collecting lubricant that drips from the brush. The brush is preferably rotated by a motor.

Abstract: A laser material for a solid-state laser that, when pumped by light having a wavelength in a suitable pump band, emits electromagnetic radiation having a wavelength lying in the range 2.0.ltoreq..lambda..ltoreq.2.1 .mu.m. The laser host material includes thulium-doped lutetium yttrium aluminum garnet (Tm:LuYAG) of approximate chemical composition (Tm.sub.x (Y.sub.w Lu.sub.1-w).sub.1-x).sub.3 Al.sub.5 O.sub.12, with x lying approximately in the range 0.01.ltoreq.x.ltoreq.0.5 and w lying in the range between 0.01 and 0.99. In particular, the Tm:LuYAG material produces light with wavelengths in the range .lambda.=2.020-2.024 .mu.m, where the normally-absorbing atmosphere has a transmission window with markedly reduced (or, alternatively, markedly enhanced) absorption. Another suitable group of laser materials has the chemical composition (Tm.sub.x (Y.sub.w Lu.sub.1-w-z Sen.sub.z).sub.1-x).sub.3 Al.sub.5 O.sub.12, with x lying approximately in the range 0.01.ltoreq.x.ltoreq.0.5, w lying in the range 0.01.ltoreq.

Abstract: Apparatus and method for modulating the phase or the amplitude of a monochromatic light beam, the apparatus including in one embodiment a Mach-Zehnder interferometer that consists of two beam splitters or beam combiners, a fully reflective mirror and an electro-optical crystal for modulation of one of two beam components. The electro-optical crystal serves as an optical resonator for the portion of the light beam admitted into the crystal material, using total internal reflection of the light beam from two or more of the crystal surfaces. The crystal has a high finesse so that a relatively small change in voltage applied across the crystal produces a large (.apprxeq.180.degree.) change in the external phase shift associated with the modulated component of the light beam.

Abstract: A blind mate shielded input/output connector assembly is disclosed for use in the robotic assembly of an electrical component, such as a radio, to electrical conductors, such as electrical wires in a harness in an automobile. The connector assembly includes a header which can be fixedly mounted to the electrical component and which includes an alignment post protruding beyond printed circuit board pins located in the header. A receptacle module includes cavities for receiving multi-contact electrical connectors and an alignment cavity into which the alignment post can be inserted. The receptacle module is mounted to a carrier panel beyond which conductors in the harness extend so that the receptacle module can move in any direction within the plane of the panel, thus permitting alignment during straight line movement of the header toward the panel. The receptacle module can also be used to provide EMI shielding and a filter can be mounted in the header.

Abstract: In a laser, the laser gain member is optically pumped by a semiconductive source of pumping radiation having an elongated output beam aperture such as that provided by a single-wide stripe diode or diode array. The elongated beam of optical pumping radiation is twice reflected from a concave surface at non-normal angles of incidence and then focused onto the laser gain material for pumping same. The reflections serve to differentially focus rays diverging in the vertical plane from rays diverging in the horizontal plane to shape the pumping beam for improved pumping efficiency in the pumped mode volume of the laser gain material. In a preferred embodiment, a magnifying lens is disposed inbetween the source and the reflectors for decreasing the divergence of the pumping beam.

Abstract: A blind mating connector for simultaneously providing electrical and mechanical connection of an electrical component to an instrument panel is disclosed such that a robotic installation of the electrical device is possible. A floating receptacle in the panel is located at a theoretical center at which the device-end connector is expected to arrive by means of resilient O-rings contained in grooves on flanges extending from the floating receptacle. The floating receptacle is movable in any direction in the plane of the panel and is rotatable about any axis. Thus, errors in alignment and in the insertion direction of the electrical device are tolerated while ensuring a proper electrical and mechanical connection between the device and the floating receptacle.

Abstract: In an eye-safe coherent laser radar, a laser diode optically pumps a solid state non-planar ring laser to produce the coherent output laser radiation. The laser radiation is passed through a Faraday isolator to an optically pumped slab three-stage linear amplifier imparting 56 db gain. A telescope transmits the amplified laser radiation to illuminate a target. Optical radiation returned from the target is collected by the telescope and focused into a single transverse mode fiber-optic waveguide for combination in the fiber with reference lasant radiation by means of a single mode fiber coupler. The combined optical radiation is then detected by a photodetector to produce a difference frequency output representative of parameters of the target.

Abstract: An optical resonator, preferably of a solid state laser, is tuned by one or more sheets of piezo-electric material bonded to one or more tuning facets of an optically transparent solid state member portion of the resonator. A tuning voltage applied across the piezo-electric sheet tends to change the area of the bonded interface of the sheet to generate a set of tuning forces predominantly in the plane of the surface of the tuning facet. These tuning forces are transmitted through the tuning facet into the solid state portion of the optical resonator to produce a change in its refractive index and dimensional change which tunes the frequency of the optical resonator and the laser using same, if any. In a preferred embodiment, the piezo-electrically tuned optical resonator is an optically pumped ring resonator made of a lasant material such as Nd:YAG for tuning the output frequency of the ring laser.

Abstract: In a monolithic optical ring resonator an optically transparent member is faceted so that the input and output beams of the resonator are coupled through a common facet at widely divergent angles in excess of 45 degrees and preferably 90 degrees. In this manner the resonator is miniaturized. The ring resonator member is contained in an evacuated housing to eliminate time-varying convective thermal detuning effects. The ring resonator is coupled in heat-exchanging relation with heating and temperature sensing film resistors deposited upon a major face of a substrate member.