Abstract: Laser apparatus including two different, pulsed MOPAs, one having a fundamental wavelength of 1064 nm and the other having a fundamental wavelength of 1564 nm, provide trains of optical pulses. The 1064-nm pulses are frequency tripled to 355 nm and the 1564-nm pulses are frequency doubled to 782 nm. The 355-nm and 782-nm pulses are mixed to provide 244-nm pulses. The 244-nm pulses are mixed with residual 1064-nm pulses to provide 198-nm output pulses of the apparatus. The output pulses can be either digitally modulated or amplitude modulated by controlling the phase relationship between the 1064-nm and 1564-nm pulses.

Abstract: Arrangements for combination and fast-axis alignment of fast-axes of diode-laser beams are disclosed. Alignment arrangements include providing each diode-laser with a corresponding alignable fast-axis collimating lens, providing individually alignable mirrors for steering an re-orienting beams from each diode-laser, and providing single diode-laser slab-modules in which the diode-laser beams can be pre-aligned to a common propagation-axis direction, and in which edges and surfaces of the slabs can be used to align the fast and slow-axes of the beams. Beam combination methods include combination by dichroic elements, polarization-sensitive elements, and optical fiber bundles.

Abstract: MOPA laser apparatus includes a master oscillator and a preamplifier providing a train of optical pulses. The pulse train is input to a fiber optic device arranged to multiply the pulse-repetition frequency (PRF) of the input pulse train. The PRF multiplying device divides each pulse in the into train into two pulses and delays one pulse relative to the other, some portion of one of the pulses and a portion of the other are delivered by the fiber optic PRF multiplying device as an output pulse-train having a PRF equal to twice the PRF of the input pulse train.

Abstract: Multiple laser resonators share a common acousto-optic Q-switch. The Q-switch is driven by a radio-frequency (RF) transducer that causes an acoustic wave to propagate in the Q-switch. Turning off the RF transducer discontinues propagation of the acoustic wave and causes each of the laser resonators to deliver an optical pulse. The finite velocity of the acoustic wave causes the pulses to be delivered temporally spaced apart.

Abstract: A method of intracavity frequency conversion in a CW laser includes causing fundamental radiation to circulate in a laser resonator. The fundamental radiation makes a first pass through an optically nonlinear crystal where a fraction of the fundamental radiation generates second-harmonic radiation in a forward pass through the crystal. The residual fundamental radiation and the second-harmonic radiation are then sum-frequency mixed in forward and reverse passes through an optically nonlinear crystal such that a fraction of each is converted to third-harmonic radiation. The residual second-harmonic radiation and fundamental radiation from the sum-frequency mixing then make a reverse pass through the second-harmonic generating crystal where the second-harmonic radiation is converted back to fundamental radiation. The third harmonic radiation can be delivered from the resonator as output radiation, or can be used to pump another optically nonlinear crystal in an optical parametric oscillator.

Abstract: A video display includes a semiconductor light-source, a pixilated spatial light modulator (SLM) for spatially modulating light from the light source and projection optics for projecting spatially modulated light from the spatial light modulator onto the screen to form the video. A desired relative brightness contribution in the display of a pixel element of the SLM is achieved by varying the power output of the light-source over a refresh-period and switching the pixel element to an on-state for a predetermined portion of the refresh-period.

Abstract: An optically pumped semiconductor pumped optical parametric oscillator (OPS-pumped OPO) includes an OPS laser resonator and an OPO resonator A portion the OPS laser resonator axis and the OPO resonator axis are collinear. An optically nonlinear crystal is located in the coaxial portion of the resonators and arranged to frequency divide fundamental radiation generated in the OPS laser resonator into signal and idler radiations. In one arrangement, the OPO laser resonator is also an OPS resonator and is arranged to generate radiation at the wavelength of the signal radiation, with the idler radiation having the difference-frequency wavelength of the signal and fundamental radiations.

Abstract: Laser apparatus is disclosed in which fundamental-wavelength optical pulses delivered from a mode-locked laser resonator at a pulse-repetition frequency (PRF) are converted to harmonic-wavelength pulses in an optical delay loop. One example is disclosed in which the harmonic-wavelength pulses are delivered directly from the delay loop. Another example is disclosed in which the harmonic-wavelength pulses are divided by the delay loop into a number of temporally spaced-apart replicas thereof, and the delay loop delivers bursts of replicas of different one of the harmonic wavelength pulses at a burst-repetition frequency equal to or a multiple of the PRF of the resonator.

Abstract: A projection display including a one-dimensional light modulator includes an optical arrangement for projecting light from a laser onto the modulator in the form of a line of light. Light from the laser is divided to create in effect a two-dimensional array of mutually incoherent light sources. Light from one axis of the array is projected onto the modulator to form the length of the line of light and light from the other axis of the array is projected onto the modulator to form the width of the line of light. Division of the light is accomplished without the use of any moving component.

Abstract: A CO2 laser has a resonator mirror that oscillates about an axis perpendicular to the resonator axis through an angular range of oscillation sufficient that the resonator is only able to deliver radiation for a fraction of an oscillation period of the mirror. In one example of the laser, the oscillating mirror is an end-mirror of the resonator. In another example, the oscillating mirror is a fold mirror of the resonator.

Abstract: An in vivo screening assay for identifying an agent that interferes with T cell activation and/or -differentiation and/or modulation of other inflammatory effector cells.

Abstract: Laser apparatus is disclosed in which fundamental-wavelength optical pulses delivered from a mode-locked laser resonator at a pulse-repetition frequency (PRF) are converted to harmonic-wavelength pulses in an optical delay loop. One example is disclosed in which the harmonic-wavelength pulses are delivered directly from the delay loop. Another example is disclosed in which the harmonic-wavelength pulses are divided by the delay loop into a number of temporally spaced-apart replicas thereof, and the delay loop delivers bursts of replicas of different one of the harmonic wavelength pulses at a burst-repetition frequency equal to or a multiple of the PRF of the resonator.

Abstract: A projection video display includes a light source including an OPS-laser delivering laser radiation in multiple transverse modes (a multiple-transverse-mode OPS-laser). The display includes a spatial light modulator for spatially modulating the radiation from the multiple-transverse-mode OPS-laser in accordance with a portion of an image to be displayed. Projection optics project the spatially modulated light on a screen on which the image is to be displayed. In one example the OPS-laser is a diode-laser array pumped OPS-laser and is one of three lasers, one delivering red light, one delivering blue light, and the other delivering green light. The lasers are time modulated such that the spatial light modulator receives light from each of the lasers separately. The OPS laser is directly time modulated by periodically turning the diode-laser array on and off.

Abstract: A CO2 laser has a resonator mirror that oscillates about an axis perpendicular to the resonator axis through an angular range of oscillation sufficient that the resonator is only able to deliver radiation for a fraction of an oscillation period of the mirror. In one example of the laser, the oscillating mirror is an end-mirror of the resonator. In another example, the oscillating mirror is a fold mirror of the resonator.

Abstract: A projection video display includes a light source including an OPS-laser delivering laser radiation in multiple transverse modes (a multiple-transverse-mode OPS-laser). The display includes a spatial light modulator for spatially modulating the radiation from the multiple-transverse-mode OPS-laser in accordance with a portion of an image to be displayed. Projection optics project the spatially modulated light on a screen on which the image is to be displayed. In one example the OPS-laser is a diode-laser array pumped OPS-laser and is one of three lasers, one delivering red light, one delivering blue light, and the other delivering green light. The lasers are time modulated such that the spatial light modulator receives light from each of the lasers separately. The OPS laser is directly time modulated by periodically turning the diode-laser array on and off.

Abstract: A longitudinal diode-laser array includes a plurality of diode-laser emitter groups. The emitter groups are mounted on corresponding electrical contacts electrically isolated from each other on a dielectric carrier. The emitter groups are cut from a conventionally formed diode-laser bar bonded to the carrier. The emitter-groups are connected together in electrical series via the electrically isolated electrical contacts. This provides that the diode-laser array can be operated at a lower current than would be required to operate the conventional diode-laser bar wherein the plurality of emitters must be connected in parallel.

Abstract: A wavelength-locking arrangement for a diode-laser bar includes a cylindrical fast-axis collimating lens and a fast-axis corner reflector. An optical filter is located between the cylindrical lens and the corner reflector for defining the locked wavelength. The corner reflector provides that radiation emitted by each of the diode-lasers and collimated by the cylindrical lens is reflected back to the cylindrical lens and is focused by the cylindrical lens back into the diode-laser from which the radiation was emitted, independent of the fast-axis alignment of the diode-laser with the cylindrical lens.

Abstract: Arrangements for combination and fast-axis alignment of fast-axes of diode-laser beams are disclosed. Alignment arrangements include providing each diode-laser with a corresponding alignable fast-axis collimating lens, providing individually alignable mirrors for steering an re-orienting beams from each diode-laser, and providing single diode-laser slab-modules in which the diode-laser beams can be pre-aligned to a common propagation-axis direction, and in which edges and surfaces of the slabs can be used to align the fast and slow-axes of the beams. Beam combination methods include combination by dichroic elements, polarization-sensitive elements, and optical fiber bundles.

Abstract: An optically pumped semiconductor pumped optical parametric oscillator (OPS-pumped OPO) includes an OPS laser resonator and an OPO resonator A portion the OPS laser resonator axis and the OPO resonator axis are collinear. An optically nonlinear crystal is located in the coaxial portion of the resonators and arranged to frequency divide fundamental radiation generated in the OPS laser resonator into signal and idler radiations.

Abstract: In a miniature Q-switched, pulsed laser, having a two arm folded resonator, Q-switching is effected by rapidly and reciprocally tilting a resonator mirror of the laser about an axis perpendicular to the axis of the laser resonator. The angular excursion of the tilting and the frequency of the tilting are selected cooperative with dimensions of the resonator to maximize energy and symmetry of intensity distribution in Q-switched pulses delivered by the laser. Rapid reciprocal tilting of the mirror is accomplished using a piezoelectrically-driven, MEMS scanner operated in a resonant mode.