Abstract: An optically-pumped mode-locked fiber ring laser for optical clock recovery of multiple wavelength division multiplexed optical signals actively mode-locks a plurality of outputs of the laser as a plurality of recovered clocks for a plurality of the multiple wavelength division multiplexed optical signals.

Abstract: Tunable semiconductor lasers are disclosed requiring minimized coupling regions. Multiple laser embodiments employ ring resonators or ring resonator pairs using only a single coupling region with the gain medium are detailed. Tuning can be performed by changing the phase of the coupling coefficient between the gain medium and a ring resonator of the laser. Another embodiment provides a tunable laser including two Mach-Zehnder interferometers in series and a reflector coupled to a gain medium.

Abstract: The method and system operate to maintain a widely tunable laser (WTL) at a selected transmission wavelength. To lock the WTL to an ITU grid line, a portion of the output beam from the WTL is routed through the etalon to split the beam into a transmission line for detection by an etalon fringe detector. Another portion of the beam is routed directly to a laser wavelength detector to determine the power of the beam. A wavelength-locking controller compares signals from the two detectors and adjusts the temperature of the etalon to align the wavelength of one of the transmission lines of the etalon with the wavelength of the output beam, then controls the WTL in a feedback loop to lock the laser to the etalon line. The wavelength-locking controller thereafter monitors the temperature of the etalon and keeps the temperature constant to prevent any wavelength drift attributable to the etalon.

Abstract: An integrated dual source recycling system and method for a chemical oxygen-iodine laser system is described. The recycling system primarily includes: (1) a first collection system for collecting an amount of spent basic hydrogen peroxide comprised of spent aqueous potassium chloride; and (2) a second collection system for collecting an amount of the spent laser exhaust gas. Several processing systems are also employed to convert the spent aqueous potassium chloride and the spent laser exhaust gas into hydrogen peroxide and potassium hydroxide which are mixed together to form fresh basic hydrogen peroxide. Additionally, the spent laser exhaust gas is recycled back into molecular nitrogen, molecular iodine, molecular oxygen, and molecular chlorine.

Abstract: A laser oscillator that, in accordance with a laser output instruction value or a current instruction value that is input, excites a laser medium and obtains a desired laser output comprises: reference waveform generation unit for employing the laser output instruction value or the current instruction value to generate a laser output waveform and a current waveform, which are references; a first comparison unit for obtaining, as a current monitor value, a current value used to excite the laser medium, and for comparing the current value with the current wave form generated by the reference wave form generation unit; and a second comparison unit for fetching, as a laser output monitor value, the value of a laser that is output by exciting the laser medium, and for comparing the value for the laser with the laser output waveform generated by the reference waveform generation unit, wherein an abnormality is detected.

Abstract: Included are a light-emitting circuit having a laser diode (LD); an LD drive circuit for driving the light-emitting circuit; a bias circuit for adding a bias current to a pulse current outputted from the LD drive circuit; a light-receiving circuit for receiving monitoring light outputted from the light-emitting circuit; an I/V conversion circuit for subjecting an output from the light-receiving circuit to current-to-voltage conversion; a maximum-value detection circuit and an average-value detection circuit for respectively detecting the maximum and minimum values of an output voltage of the I/V conversion circuit; a first comparator for comparing the detected maximum value with a first reference value to feed back the comparison result to the LD drive circuit; and a second comparator for comparing the detected average value with a second reference value to feed back the comparison result to the bias circuit.

Abstract: A method for manufacturing a semiconductor device including, forming a photosensitive-film on a substrate, carrying the substrate on which the photosensitive-film is formed, to an exposure device provided with a mask in which an on-mask-inspection-mark and an on-mask-device-pattern are formed, selectively exposing the photosensitive-film to light to transfer the on-mask-inspection-mark to the photosensitive-film to form a latent-image of the inspection-mark on the photosensitive-film, heating at least that area of the photosensitive-film in which the latent-image of the inspection-mark is formed, measuring the inspection-mark, changing set-values for the exposure device used for the selective exposure, on the basis of result of the measurement so that exposure conditions conform to the set-values, exposing the photosensitive-film on the basis of the changed set-values to transfer the on-mask-device-pattern to the photosensitive-film to form a latent image of the device-pattern on the photosensitive-film, heat

Abstract: Apparatus for projecting a line of light includes a linear array of diode-lasers arranged in a diode-laser bar. The apparatus includes an optical system. Components of the system include a plurality of lenses and array of cylindrical microlenses having the same spacing as diode-lasers in the diode-laser array. The microlens array is spaced at a distance from the diode-laser bar and aligned with the diode-laser bar such that the front focal plane of the microlens array is between the diode-laser bar and the microlens array. The optical system components are configured and arranged to project overlapping elongated images in a predetermined plane. The overlapping images form the line of light. The elongated images are images of cross-sections of beams from the diode-lasers where the beams are intersected by the front focal plane of the microlens array.

Abstract: A laser diode array is formed on a substrate (310) in which a number of parallel grooves (312) are formed. A metal layer (410) is formed on the grooves (312). Laser diode bars (314) are fitted in alternate grooves, and every other groove is left vacant to serve as a cooling channel (316). The array is immersion cooled in a housing (210). Liquid coolant is circulated through the housing (210) and through a heat exchanger (216). The liquid coolant flows over a major surface of the substrate (310) and through the cooling channels (316). Thus, heat is removed by circulating fluid from three sides of the laser diode bars (314). Such high-performance cooling permits the laser diode array to have a greater power density.

Abstract: The generation of ultrabright, multikilovolt coherent tunable x-radiation resulting from amplification on hollow atom transition arrays is described. Amplification has been demonstrated by physical evidence including (a) the observation of selected spectral components of several Xeq+ hollow atom transition arrays (q=30, 31, 32, 34, 35, 36, 37) radiated axially from confined plasma channels, (b) the measurement of line narrowing that is spectrally correlated with the amplified transitions, (c) evidence for spectral hole-burning in the spontaneous emission, a manifestation of saturated amplification, that corresponds spectrally with the amplified lines, and (d) the detection of an intense narrow (??x˜0.2 mr) directed beam of radiation in the far field of the source.

Abstract: A multi-beam laser scanning unit including a plurality of laser diodes arranged in the vertical direction, and a plurality of collimating lens units having collimating lenses, which are arranged in the laser beam optical path in order to convert laser beams emitted from each of the laser diodes into linear beams. The collimating lens units are arranged in a manner such that adjacent collimating lens units are partly overlapped in the laser beam scanning direction. Each of the collimating lenses has a different focal length.

Abstract: A single-wavelength distributed feedback (DFB) laser structure is provided. The laser structure having two sections includes an active-material layer for generating a laser having a wavelength in a specific range, two cladding layers respectively covering an upper and a bottom sides of the active-material layer for forming a waveguide structure, a phase shift layer having a specific thickness for controlling a difference between Bragg wavelengths of the two sections, a wet-etching stop layer positioned between the active-material layer and the phase shift layer, and a grating layer having a specific period for determining an illuminating wavelength, wherein a difference between the two sections is an existence of the phase shift layer thereon, and the existence of the phase shift layer causes a difference of the effective refractive indices between the two sections so as to generate a fixed difference between Bragg wavelengths of the two sections.

Abstract: A laser device includes a laser diode, and a controller that superimposes a low-frequency signal on a modulating signal applied to the laser diode. The low-frequency signal has an amplitude that correlates with an amplitude of the modulating signal.

Abstract: A wavelength stabilization module having a light-receiving element array and a method of manufacturing the same are disclosed.

Abstract: The output of a high power pulsed or CW laser (22), which may be mounted on a vehicle (17) is reflected from a convex mirror (27) to a concave mirror (29) that is displaced radially outward on a rotating structure (14) from the convex mirror by at least two beam diameters so that each pulse emanates from a position around a circle which is displaced from adjacent pulses by at least the diameter of the beam, thereby to minimize thermal blooming, or the position of a CW output laser beam is slewed. Directing the beams so that all of them will converge at a target area which is a given range from the apparatus is achieved by moving the convex mirror axially in response to range control signals provided through brushes (47) and slip rings (46). The rotating structure (14) including the laser waveguide (24) is journaled by bearings (50, 51) for rotation by a gear in response to a pinion (34) and gear reduction (37) driven by a motor (38).

Abstract: Disclosed is a distributed Bragg reflector laser, which includes: an active layer; a first guide layer provided with a plurality of first gratings on an upper surface thereof and formed on one side of the active layer; and, a second guide layer provided with a plurality of second gratings on an upper surface thereof, wherein the second guide layer is formed on the other side of the active layer opposite to the first guide layer.

Abstract: A method of enhancing wavelength tuning performance in an external cavity laser includes providing a diffractive focusing element, emitting light into the cavity of the laser at a range of angles relative to an optical axis of the cavity, and diffractively focusing the light back onto the optical axis at a wavelength-dependent focal distance using the diffractive focusing element. The method further includes confining the diffractive focusing to a high dispersivity portion of the diffractive focusing element. In various embodiments, the confining may include offsetting the diffractive focusing element radially relative to the optical axis, or selectively blocking a portion of the light emitted into the cavity at emission angles less than a threshold emission angle.

Abstract: A laser diode driver output stage for driving an associated laser diode device. In one aspect of the present invention, the laser diode driver output stage includes a driver circuit having at least one input node and an output node. The driver circuit is adapted to receive an input data signal at the at least one input node and provide an output signal at the output node in response to the data signal. The laser diode driver output stage further includes a transformer connected to the output node of the driver circuit. The transformer is adapted to receive the output signal at a first side and apply impedance compensation to the output signal to provide an output drive signal from a second side to drive the associated laser diode device.

Abstract: A digital reading and/or writing system and method for reading and/or digital data recorded on a digital recording medium. The system includes a first array having a plurality of near-field solid immersion optical lenses and a second array having a plurality organic micro-cavity lasers with the capability of light intensity modulation. The first array being positioned with respect to the second array such that each near-field optical lens of the first array is associated with at least one organic micro-cavity laser in the second array wherein each of the plurality of organic micro-cavity lasers with the capability of light intensity modulation providing light to its associated near-field solid immersion optical lens that is used for reading digital data on the digital recording medium.

Abstract: A planar wafer-level packaging method is provided for a laser and a microlens. Light from the laser is directed and shaped by the microlens to couple into an external light guide. A plurality of such assemblies, each comprising a laser and a microlens may be assembled on a single planar substrate. A tapered surface is formed on the microlens. The microlens may be formed from a silicon substrate. The angle of the tapered surface causes an accurate cone or pyramid shape. The tapered surface is formed such that the axis of the cone or pyramid is aligned with the optical axis of the lens. The lens may then be aligned with the optical axis of the laser. A light guide receptacle is formed with a tapered surface that matches the tapered surface of the microlens. The tapered surface of the receptacle is formed such that the axis of the cone or pyramid is aligned with the optical axis of the receptacle. The receptacle may then be passively aligned with the microlens by mating the tapered surfaces.