Abstract: The invention features an apparatus and an associated method for illuminating a target area. The apparatus includes reflectors defining a first optical cavity. The first optical cavity defines a first set of longitudinal modes. The apparatus includes a first gain medium defining a first gain band. The first gain medium is configured to cause a plurality of the longitudinal modes of the first set to oscillate over an oscillation band within the first gain band when the first gain medium is pumped at an operative level. The apparatus includes a first optical waveguide positioned within the first optical cavity. The first optical waveguide has a length selected to cause a temporal coherence length of light emitted from the first optical cavity to be shorter than a scattering distance associated with the target area.

Abstract: A color dazzle system to enhance area denial to personnel mission for law enforcement, homeland security, border patrol, and the military effectively by interrupting the ability of combatants to continue with their intended mission. The color dazzle system has a multi-wavelength laser module for generate desired color or wavelength ranges of light, a beam projector module for pointing the light towards the target to be dazzled, and a fiber optic beam delivery system for delivering the light to the beam projector module. By adjusting the power output according to the corresponding wavelength and the distance to the target, and quickly switching between the wavelengths of light, a dazzle effect can be obtained with an irradiance within a safety range for the eye.

Abstract: An integrated circuit lithography technique called spectral engineering by Applicants, for bandwidth control of an electric discharge laser. In a preferred process, a computer model is used to model lithographic parameters to determine a desired laser spectrum needed to produce a desired lithographic result. A fast responding tuning mechanism is then used to adjust center wavelength of laser pulses in a burst of pulses to achieve an integrated spectrum for the burst of pulses approximating the desired laser spectrum. The laser beam bandwidth is controlled to produce an effective beam spectrum having at least two spectral peaks in order to produce improved pattern resolution in photo resist film. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection control system having a time response of less than about 2.0 millisecond.

Abstract: Optical filaments are formed controllably in a gaseous medium such as air. A phase plate introducing a phase discontinuity or other localized optical inhomogeneity is introduced into the path of the pulsed high-power laser beam that forms the optical filaments in the medium. The locations and characteristics of the phase discontinuities or singularities are selected to control the number and locations of the optical filaments.

Abstract: A semiconductor laser unit includes a plurality of semiconductor laser elements arranged parallel with one another in a laser beam-emitting direction, and a base for positioning and fixing the plurality of semiconductor laser elements. The plurality of semiconductor laser elements are arranged such that a laser beam emitted from the semiconductor laser element greatest in astigmatism, of the plurality of semiconductor laser elements, is coincident in its axis with a reference axis of the base. In the case that the semiconductor laser unit is arranged on an optical head device, the focusing characteristic on the plurality of laser beams can be improved.

Abstract: A symmetrization device and laser diode system using such a device is shown. The device has adjacent lens components transforming beamlets from a laser diode array. Each lens component has input and output surfaces, each having a profile in the propagation direction of the beamlets and a contour perpendicularly thereto. The profiles of the input and output surfaces and distances therebetween are selected to permute the divergence along the slow and fast axes of the beamlets. The contour of each surface matches the cross-sectional shape of the beamlets thereat.

Abstract: A multi-layered reflective mirror formed of spaced-apart plate-shaped empty space patterns formed within a substrate is disclosed. The plurality of plate-shaped empty space patterns are formed by drilling holes in the substrate and annealing the substrate to form the spaced-apart plate-shaped empty space patterns.

Abstract: A laser display device is provided which includes: a light source emitting at least one laser beam; a light modulation unit for modulating the laser beam emitted from the light source according to an image signal; a scanning unit scanning the laser beam modulated in the light modulation unit in a main scanning direction and in a sub-scanning direction; and an image unit in which an image is formed having a phosphor layer in which excitation light is generated by a laser beam scanned by the scanning unit.

Abstract: In apparatus for wavelength stabilizing and spectrally narrowing an output beam of a diode-laser, a cylindrical lens is arranged to collimate the beam in the fast axis of the diode laser without reducing divergence in the slow axis of the diode-laser. An optical fiber is arranged to receive the fast-axis collimated beam from the lens. The optical fiber has a multimode core surrounded by a first cladding, the first cladding being surrounded by a second cladding. The core of the optical fiber includes a wavelength selective Bragg grating and has a numerical aperture of about 0.06 or less. The optical fiber has a numerical aperture of about 0.15 or greater. The fast-axis collimated beam and the relatively low numerical aperture of the core provide that the Bragg grating only reflects light that propagates about parallel to the longitudinal axis of the fiber. Light reflected from the grating is fed back to the diode-laser for stabilizing the wavelength and spectrally narrowing the diode-laser output beam.

Abstract: In apparatus for wavelength stabilizing and spectrally narrowing an output beam of a diode-laser, a cylindrical lens is arranged to collimate the beam in the fast axis of the diode laser without reducing divergence in the slow axis of the diode-laser. A length of optical fiber is arranged to receive the fast-axis collimated beam from the lens. The optical fiber has a core surrounded by a first cladding, the first cladding being surrounded by a second cladding. The core of the optical fiber has an elongated cross section and includes a wavelength selective Bragg grating. The core functions as a low-mode core in the width direction of the cross section. The length direction of the core is aligned with the fast axis of the diode-laser. The fast-axis collimated beam and the low mode width of the core provides that the Bragg grating only reflects light that propagates parallel the longitudinal axis of the fiber.

Abstract: A laser beam containment system includes a number of optics that direct a laser beam produced by a laser beam source along a path to a point of application of the laser beam. One or more hollow tubes are positioned in an arrangement such that the laser beam passes through the hollow tubes. The hollow tubes are also adjustably positioned relative to the laser beam objects to allow for access to the optics for maintenance and adjustment of the optics. Locking mechanisms provide control of the adjustment features of the containment tubes.

Abstract: A wavelength reference filter for receiving an input signal and producing a filtered output signal is provided. The operation of the filter is independent of the angle of incidence of the input signal. As a result, the output signal from the filter will maintain its wavelength, even under changes in the direction of propagation of the input signal to the filter. Without such incidence angle independence, a change to the input signal would change the output signal and result in inaccurate device operation. Example incidence angle independent filters may include a single etalon or multiple etalons. In the former example, a signal may traverse a single etalon twice, along paths that have different angular sensitivities relative to the etalon. In the latter example, each etalon may have an equal and opposite angular sensitivity, such that two the etalons have canceling angular sensitivities.

Abstract: Multiple laser beams, each having a shape such as a Gaussian profile, can be incoherently combined to obtain a shaped, flat top laser beam. The combined laser beams can provide power levels necessary for material processing applications such as annealing, drilling, and cutting, while minimizing the amount of unused power. The lasers can be positioned in an array in order to shape the flat top beam, and can be staggered in position where necessary to give each output beam an equal beam path length. The relative frequencies and/or powers of the lasers can be adjusted to control the flatness and stability of the incoherently combined beam.

Abstract: A laser drilling system for flexible printed circuit board includes a first mirror, a second mirror, a laser crystal, a third harmonic generator and a second harmonic generator. The first mirror and the second mirror are spaced apart and defined a resonator cavity therebetween. The laser crystal is disposed in the resonator cavity for generating a fundamental laser beam. The third harmonic generator and the second harmonic generator are disposed the resonator cavity. A fundamental laser beam is directed to the second harmonic generator for generating a second harmonic laser beam, the fundamental laser beam and the second laser harmonic laser beam is directed to the third harmonic generator for generating a third harmonic laser beam, the third harmonic laser beam is output from the resonator cavity. A laser drilling method for flexible printed circuit board is also provided.

Abstract: The invention relates to a laser processing device that can change the diameter of a beam spot on an object to be processed, without using a mechanism for changing a distance between a condensing lens and the object. A beam emitted from a laser beam source is condensed by the condensing lens, and is made incident to an optical fiber. The beam emitted from the optical fiber is condensed by a condensing optical system onto an object to be processed. The object is welded using the condensed beam. The laser processing device comprises an adjusting unit that can change the angle of divergence of the beam on the emission surface of the optical fiber. The adjusting unit changes the angle of divergence of the beam, thereby to change the diameter of the beam spot formed on the surface of the object.

Abstract: An apparatus and method for monitoring light beams comprising a reflector for passing at least partially through the beam to reflect a sample of the beam and at least one sensor arranged to receive the reflected beam sample for determining a characteristic of the beam sample. The reflector may be arranged to oscillate and the sensors may he arranged at substantially forty-five or ninety degrees to the axis of the incident beam.

Abstract: A spatial filter adapted to increase the angular spread of non-conjugated energy in a beam and suppress this energy to improve the efficiency of a phase conjugate system. In the illustrative embodiment, the filter includes first and second lenses and an aberrator to increase the angular spread. In the specific embodiment, an opaque plate, with a pinhole aperture therethrough, is sandwiched between the lenses to suppress the non-conjugated energy. The aberrator may be implemented with an amplifier or other suitable mechanism. Likewise, the aperture may be replaced with a highly angle-selective thick Bragg grating or other suitable arrangement. A phase conjugate master oscillator/power amplifier laser architecture is also disclosed.

Abstract: There is provided a phase control portion for controlling phase of a laser beam resonated in a resonator based on detected results by two optical detectors. The phase control portion adjusts the longitudinal mode positions by a feedback control so that a ratio of intensities detected by the two optical detectors comes to a predetermined reference value. To one of the optical detectors, part of a laser beam outputted from the resonator is irradiated as it is, whereas, to the other one of the optical detectors, part of the laser beam outputted from the resonator is irradiated after passing through an etalon. An FSR of the etalon is a double of that of another etalon in the resonator.

Abstract: Method and apparatus for creating a clone relationship between two or more optical-frequency comb sources (OFCSs). In one embodiment, the invention is an apparatus having (i) first and second OFCSs, each adapted to generate a respective frequency comb, and (ii) means for locking the phases of two comb lines of the first OFCS and the phases of the respective two comb lines of the second OFCS to create a full or partial clone relationship between these two OFCSs. In one system configuration, the locking of the phases of the first and second OFCSs is achieved by locking the phases of two selected comb lines generated by each of these OFCSs to the phases of the respective comb lines generated by the same (third, reference) OFCS.

Abstract: A laser apparatus is disclosed. The apparatus includes a Neodymium-doped lasing material having first and second surfaces and a passive Q-switch optically coupled to the second surface. The first-surface is substantially transparent to a pump radiation and substantially reflective to laser radiation generated by an interaction between the pump radiation and the Neodymium-doped lasing material. The laser radiation is characterized by a vacuum wavelength corresponding to an atomic transition from the 4F3/2 level to the 4I9/2 level of Neodymium in the lasing material. The second surface transmits at least a portion of the laser radiation. The lasing material and Q-switch are configured to produce pulses of the laser radiation characterized by a pulse length of greater than zero and less than about 1.5 nanoseconds and a pulse repetition rate greater than about 100 kHz. A PQSL laser, an apparatus for generating blue light and a display system based on the laser apparatus are also disclosed.

Abstract: The present invention provides a system, method and apparatus for improved electrical-to-optical transmitters (100) disposed within printed circuit boards (104). The heat sink (110, 200) is a thermal conductive material disposed within a cavity (102) of the printed circuit board (104) and is thermally coupled to a bottom surface (112) of the electrical-to-optical transmitter (100). A portion of the thermal conductive material extends approximately to an outer surface (120, 122 or 124) of a layer (114, 116 or 118) of the printed circuit board (104). The printed circuit board may comprise a planarized signal communications system or an optoelectronic signal communications system. In addition, the present invention provides a method for fabricating the heat sink wherein the electrical-to-optical transmitter disposed within a cavity of the printed circuit board is fabricated. New methods for flexible waveguides and micro-mirror couplers are also provided.

Abstract: A cavity ring-down spectrometer includes: a) multiple detectors for monitoring the intensity of the radiation emitted from the cavity and the wavelength of the radiation injected into the cavity; b) controllers which turn off the radiation into the cavity and precisely adjust the temperature of, and current to, the laser gain medium; and c) means for adjusting the beam path length of the optical cavit to bring the cavity into resonance with the injected radiation. Additionally, disclosed is a method for using the spectrometer to detect a target analyte.

Abstract: A laser machining apparatus in which laser output can be easily corrected in view of secular change of components of the laser machining apparatus and influence of temperature. Output values of a laser oscillator operated according to a reference laser output command value Psc are stored as reference output values P(?) at different temperatures ? in a table TB1. When the laser oscillator is started up, a measured output value Pr of the laser oscillator supplied with the reference command value Psc is obtained, and a new correction coefficient k is obtained to replace an old one. From a reference output value P(?) at a temperature at that time and the actual output measured value Pr, a correction value ?P is obtained and stored.

Abstract: When a piezoelectric element 3 applies an external force to a plastic photonic crystal, the photonic crystal deforms, and accordingly, the photonic band gap easily changes. When the photonic band gap changes, transmission of light with a specific wavelength is limited. Therefore, light with a desired wavelength is outputted from the photonic crystal 2 upon sufficient tuning, and extracted to the outside through an output window 6. In the present invention, a plastic photonic crystal 2 which can achieve sufficient wavelength tuning although it is small is used, and elements are unitized, so that the entire wavelength tunable light source unit is downsized.

Abstract: A laser is disclosed which includes a gain medium, a switch element, and a pulse controller. In one embodiment laser light of differing polarizations pass along respective paths and a pulsed laser output is generated via an electro-optical element. In another embodiment light of differing polarizations passes in differing directions through a cyclical path. The invention can make use of a prism-shaped polarizer having a polarization selection face and two further faces. Yet further initial pulses can be controlled to reduce energy, for example by progressively increasing the period or amplitude of successive pulses. As a result an efficient and high power laser apparatus is realized.

Abstract: A semiconductor laser apparatus according to an exemplary embodiment of the present invention is provided. For example, the apparatus may include a single or a plurality of stacked-array laser diodes, first beam compressors, and a separating optical device separating the group of laser beams into subgroups of laser beams in a first direction, and deflecting the subgroups of laser beams so that the subgroups of laser beams approach in the first direction and recede from one another in a second direction. In addition, a collimating optical device may be provided which is adapted to deflect the subgroups of laser beams in the first and second directions by the same angles. Further, a beam converter may be included which divides each subgroup of laser beams and turning the axis thereof, and second beam compressors and a group of cylindrical lenses can be provided that can make the angle of divergence in the first direction close to the angle of divergence in the second direction.

Abstract: A technique for bandwidth control of an electric discharge laser. Line narrowing equipment is provided having at least one piezoelectric drive and a fast bandwidth detection means and a bandwidth control having a time response of less than about 1.0 millisecond. In a preferred embodiment wavelength tuning mirror is dithered at dither rates of more than 500 dithers per second within a very narrow range of pivot angles to cause a dither in nominal wavelength values to produce a desired effective bandwidth of series of laser pulses.

Abstract: An apparatus for shaping the output beam of a strip of lasers, or an array of such strips, comprising a first reflective member including at least a first reflective element for deflecting a first portion of the output beam in a first direction oriented at a first angle in the slow axis direction and at a second angle in the fast axis direction, and at least a second reflective member including at least a first reflective element for deflecting the first output beam portion from the first direction to a second direction in the Z axis. The output beam is thus shaped to define at least two beams comprising at least the first portion and a remainder of the output beam which is propagated along the Z axis without deflection by any reflective member, with the first portion of the output beam being oriented approximately parallel to the un-deflected remainder.

Abstract: A transmitter optical subassembly includes an optical emitter and a fiber receptacle within which an optical fiber is received. An optical limiting element is positioned between the optical emitter and the fiber receptacle. When an optical signal is emitted from the optical emitter, the optical signal passes through the optical limiting element before the optical signal reaches the fiber receptacle and is received by the optical fiber. The optical limiting element has a property such that if the power of the optical signal entering the optical limiting element exceeds a predetermined limit, the power of the optical signal is optically attenuated so that the power of the optical signal exiting the optical limiting element remains below a predetermined limit.

Abstract: Controller calibration methods for use with sampled grating distributed Bragg reflector SGDBR laser (102) is presented. An exemplary method includes conducting a two-dimensional mirror current scam of each front mirror current setting and back mirror current setting for a sampled grating distributed Bragg reflector SGBDR laser(102) to produce laser setting data corresponding to each front mirror current setting and back mirror current setting to generate a reference optical signal (114) of the SGDBR laser (102). A channel operating point is determined for each channel within the two-dimensional scan data. A fix up of the operating point to substantially minimize wavelength and power error can also be performed. A two-dimensional control surface is characterized at the channel operating point for each channel. A lookup table for controlling the SGDBR (102) laser is generated from the operating point currents, locker values and two-dimensional control surface data from each channel.

Abstract: Optical filaments are formed controllably in a gaseous medium such as air. A phase plate introducing a phase singularity is introduced into the path of the laser beam that forms the optical filaments in the medium. The phase plate is preferably a vortex phase plate having one or more singularities. The locations and characteristics of the phase singularities are selected to control the number and locations of the optical filaments.

Abstract: A method for adjusting the relative output power of individual output wavelengths of a multi-output-wavelength Raman laser (10) is disclosed. The method is characterized by the steps of suppressing the relative output power of a potentially most powerful output wavelength (98) in a first step (108), adjusting the relative output power of the shortest output wavelength (94) in a second step (110), adjusting the relative output power of further output wavelengths (96, 100, 102, 104) in a third step (112), and adjusting the relative output power of the potentially most powerful output wavelength (98) in a fourth step (114). Further, a device (68) that performs such a method is disclosed, i.e. a device for adjusting the relative output power of individual output wavelengths (94, 96, 98, 100, 102, 104) of such a laser (10).

Abstract: A laser is disclosed which includes a gain medium, a switch element, and a pulse controller. In one embodiment laser light of differing polarizations pass along respective paths and a pulsed laser output is generated via an electro-optical element. In another embodiment light of differing polarizations passes in differing directions through a cyclical path. The invention can make use of a prism-shaped polarizer having a polarization selection face and two further faces. Yet further initial pulses can be controlled to reduce energy, for example by progressively increasing the period or amplitude of successive pulses. As a result an efficient and high power laser apparatus is realized.

Abstract: A laser apparatus includes a laser element that emits the laser beam. A detector detects the laser beam emitted from the laser element. A controller controls the laser element such that the laser beam is oscillated subject to multiple conditions, such as the emission frequency and the energy of the laser beam, when the laser element is in a ready state, based on the detection results. In the ready state, the laser beam is not emitted from the apparatus onto a subject. Closely monitoring the oscillated beam in the ready state allows the precise beam desired to be emitted in an operational mode. The apparatus is useful for fabricating semiconductor devices.

Abstract: A laser output beam is directed into an acousto-optic cell. The acousto-optic cell is driven by RF voltages at a plurality of different frequencies. Portions of the laser output beam are diffracted by the acousto-optic cell at a plurality of different angles corresponding the different drive frequencies. The different portions of the output beam define a plurality of secondary beams. The magnitude of the RF voltages applied to the acousto-optic cell and the power in the laser output beam may be cooperatively varied to provide a predetermined power in each of the secondary beams.

Abstract: A condensing lens is integrally formed with collimator-lens portions which respectively collimate light beams and a condensing lens portion which makes the collimated light beams converge at a common point. In addition, an optically-multiplexed-laser-light source is constituted by semiconductor lasers, a multimode optical fiber, and the above condensing lens, where the collimator-lens portions in the condensing lens are respectively arranged in correspondence with the semiconductor lasers, and the condensing lens portion couples the light beams collimated by the collimator-lens portions, to the multimode optical fiber.

Abstract: A positioning system including a sensor, a drive sequencer and an actuator. The sensor senses the actuator position and provides position signals to drive the sequencer which responsively computes and drives the actuator in open loop moves containing dwell intervals of position. The actuator positions a mirror or other load means to reflect an optical beam as desired. Either preprogrammed or non-repeating sequences of actuator stopping positions can be synchronized with a laser. During dwell times, mirror position accuracy better than 10 microradians is suitable for tuning CO2 pulse burst or CW lasers.

Abstract: The present invention contemplates a method and apparatus to generate a laser probe beam free of speckles. The present invention employs a holographic phase plate inserted in a laser beam path to modulate the relative phase across the beam. The holographic phase plate is designed to optimize the phase modulation across the beam while to minimize the degradation of the beam quality. The modulated laser beam has only a small and confined divergent angle and can then be refocused or collimated into a narrow and near collimated probe beam. The present invention further rotates the holographic phase plate to randomize the speckles in a time sequence. As a result, the probe beam preserves substantially the beam quality of a laser and produces substantially no speckles on image of its, intersection with a surface or material.

Abstract: In crystallizing an amorphous silicon film by illuminating it with linear pulse laser beams having a normal-distribution type beam profile or a similar beam profile, the linear pulse laser beams are applied in an overlapped manner. There can be obtained effects similar to those as obtained by a method in which the laser illumination power is gradually increased and then decreased in a step-like manner in plural scans.

Abstract: An optical system has a transmission filter device, a feedback mechanism, and one or more radiation sources. Each radiation source generates an output signal with a predetermined wavelength band and polarization and is coupled to a separate input port of the transmission filter device. The transmission filter device, which is responsive to output signal from each radiation source, generates an output signal from at least one output port thereof. The feedback mechanism is coupled to at least one output port of the transmission filter device for providing a feedback signal that is directed back through the transmission filter device to each of the radiation sources for stabilizing each of the radiation sources. The apparatus is polarization maintaining wherein the one or more radiation sources, the transmission filter device, and the feedback mechanism are interconnected such that principle axes of polarization thereof are substantially aligned.

Abstract: An opto-electronic oscillator including a modulator for outputting modulated light and a tunable filter for receiving modulated light output from the modulator.

Abstract: In one embodiment of the present invention, an apparatus operates a control loop for a tunable optical device. A digital reference signal is converted to an analog reference signal and then introduced into the optical path of the tunable optical device. An analog feedback signal, corresponding to the digital reference signal, is recovered from the tunable optical device. The analog feedback signal is converted to a digital feedback signal. The apparatus sends tuning information to the tunable optical device based on analysis of the digital reference signal and the digital feedback signal. In one embodiment, the tuning information is used for wavelength locking of the tunable optical device. In another embodiment, the operation of the control loop is synchronized with another function of the tunable optical device.

Abstract: Wavelength lockers, which monitor the wavelength drift of a laser's beam due to aging, are tunable to adjust for manufacturing misalignments between its various optical components. Tuning is accomplished by adjusting the position of a collimating lens using a flexure. Adjusting the lens position changes the angle of incidence of a monitored beam relative to a fixed filter and detector and avoids the challenging manufacturing task of rotating the filter and detector to achieve the same result.

Abstract: An exposure apparatus has a laser device that is small, easy to maintain, and capable of producing an output that is unlikely to be affected by optical surges occurring in the beginning of operation. A single-wavelength laser oscillator (11) supplies a laser beam (LB1) to a fiber optic amplifier (13) through an optical modulator (12). The amplified laser beam is split by splitters (14, 16-1 to 16-m), amplified by optical amplifier units (18-1 to 18-n) and supplied through a fiber bundle (19) to a wavelength converter (20), which in turn converts the split beams into ultraviolet laser radiation (LB5) for use as exposure light. The optical modulator (12) outputs light pulses during the generation of ultraviolet light. The optical modulator (12) also produces laser radiation during the absence of ultraviolet light, but the laser radiation has substantially the same average output and a considerably low peak compared with that during the generation of ultraviolet light.

Abstract: Disclosed is an illuminating optical unit in an image display unit for displaying an image by irradiating a GLV (spatial modulation device) with a laser beam and modulating the laser beam based on an image signal inputted to the GLV, which includes a polarized light rotation means for equally dividing a polarized light component of the laser beam into a P polarized light component and an S polarized light component, a polarized light beam splitter for separating from each other the P polarized light component and the S polarized light component equally divided by the polarized light rotation means, and an optical path difference generation means for generating an optical path difference not less than the coherence length of the laser beam between the laser beam of the P polarized light component and the laser beam of the S polarized light component.

Abstract: A semiconductor laser array is located beside a solid state laser element, and an optical resonator for excitation light includes a coating highly reflective to an oscillation wavelength of the semiconductor laser array on an end face of the semiconductor laser array, opposite from the solid state laser element and a side of the solid state laser element. The solid state laser element is located inside of the optical resonator, and the solid state laser element is excited optically by the excitation light.

Abstract: Speckle of a laser beam is reduced by inserting an anti-speckle apparatus in the beam path to disrupt its spatial coherence while maintaining its temporal coherence. In one embodiment, the anti-speckle apparatus is a phase retarder plate bearing periodic optically-coated regions. Transmission or reflection of the beam through coated and uncoated regions causes an internal phase shift of first beam portions relative to second beam portions, thereby disrupting spatial coherence. Size and thickness of the coated regions can be carefully tailored to meet requirements of stepper and scanner equipment manufacturers for maximum allowable spatial coherence expressed as a minimum permissible number of coherent cells across the beam cross-section. An alternative embodiment of an anti-speckle apparatus is a scattering plate bearing a roughened surface. Transmission or reflection of the beam by the roughened surface disrupts the beam's spatial coherence.

Abstract: An optical switching apparatus comprises an optically resonant system (3, 12) and a pulse source configuration (1, 2) to direct first and second pulses (P1, P2) of optical radiation into the resonant system, the first pulse (P1) being configured to produce a coherent excitation of the resonant optical system so as to change its optical characteristics and the second pulse (P2) being of a phase to thereafter de-excite the coherent excitation produced by the first pulse. According to the invention, a device (13, 34) driveable externally of the resonant system such as an optical amplifier or a laser, maintains the coherence of the excitation produced by the first pulse until de-excited by the second pulse. The optically resonant system may comprise an optically responsive medium (3) which is capable of being switched into a state of coherent resonance or a resonant cavity.

Abstract: An optical system for a laser comprises at least means for imaging a laser beam onto a first optical material (1, 1b). These imaging means comprise at least one optical image system (2) for focusing said laser beam onto the first optical material (1, 1b) and at least one optical means for changing the angle of the propagation axis of the laser beam, whereby the optical imaging system is positioned between the optical means and the first optical material, and may be described by formula (I) whereby D is substantially zero ( AB CD ) - matrix .

Abstract: A system and method for selectively process material on a processing surface of a printing form to create a fine structure or pattern for images or text. At least one fiber laser comprising a pump source and a laser fiber is provided. A laser gun is mounted adjacent the printing form and has at least a focusing optics. The fiber laser outputs a laser beam which is diffraction-limited to permit the focusing optics to focus the laser beam onto the processing surface of the printing form as a spot having a spot size sufficiently small to process the processing surface to create the fine structure or pattern images or text.