Abstract: A compact optical resonator that exhibits long TOPLs is fabricated by (a) selecting a 3-dimensional (3D) reflective, essentially closed surface such that the paths of optical rays that reflect from the interior of the surface include chaotic, open paths; (b) determining the phase-space of the reflection points of the rays; (c) within the phase-space identifying at least one forbidden zone where there are no such reflection points and at least one allowed zone where there is a multiplicity of such reflection points; (d) forming the surface inside a rigid body; and (e) forming at least one physical feature that communicates with the interior of the resonator and is located in a region of the surface that is determined by the positions of the forbidden zones, the allowed zones, or both. In a preferred embodiment physical features such as gas ports are located in regions of the surface that, in phase space, correspond to forbidden zones (so that the circulating optical rays cannot escape via the gas ports).

Abstract: The present invention provides an excimer laser capable of producing a high quality pulsed laser beam at pulse rates of about 4,000 Hz at pulse energies of about 5 mJ or greater. A preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter with special software monitors output beam parameters and controls a very fast PZT driven tuning mirror and the pulse power charging voltage to maintain wavelength and pulse energy within desired limits. In a preferred embodiment two fan motors drive a single tangential fan which provides sufficient gas flow to clear discharge debris from the discharge region during the approximately 0.25 milliseconds between pulses.

Abstract: A semiconductor laser source includes a laser diode having front and rear facets. The laser diode includes a substrate and a lower cladding layer disposed on the substrate. The lower cladding layer is doped with a dopant of the first conductivity type. An active layer is disposed on the lower cladding layer and an upper cladding layer is disposed on the active layer. The upper cladding layer is doped with a dopant of the second conductivity type. At least one electrode is disposed on a first outer layer of the diode. A pair of electrodes is disposed on a second outer layer of the diode. The second outer layer is located on a side of the diode opposing the first outer layer. The pair of electrodes is configured to allow application of different currents to each one of the electrodes in the pair of electrodes. A reflector, which is located external to the laser diode, is in optical communication with the front facet of the laser diode for providing optical feedback to the active region.

Abstract: A continuous wave laser device (40) comprises a convoluted path or fiber (43) of Raman laser material that has been micromachined on to a substrate, the laser material fiber being covered by protective cladding (30). A 1 cm diameter substrate can have tens of meters of fiber fabricated on it and with a suitable choice for the laser material, e.g. Diamond, can output tens of hundreds of Watts of laser power. One possible use envisaged is as multicolor laser diodes, for example for projection television systems.

Abstract: Apparatus for single photon source based on emitters with frequencies distributed in a chosen manner. In one embodiment, the apparatus comprises an opto-electronic component capable or emitting light pulses containing a single photon comprising a resonant optical cavity and a group of photon emitters placed in this optical cavity, a single one of these emitters having an emission frequency equal to approximately the resonant frequency of the cavity characterised in that all emitters have a spectral distribution with a concentration of emitter frequencies at a given frequency, and in that the cavity is made so that its resonant frequency is different from this concentration frequency so that the number of emitters with an emission frequency corresponding to the resonant frequency of the cavity is close to one.

Abstract: The invention is directed to a method for energy regulation of pulsed-operation gas discharge-coupled radiation sources, particularly of excimer lasers, F2 lasers and EUV radiation sources. The object of the invention is to find a novel possibility for energy regulation of pulsed-operation gas discharge-coupled radiation sources which permits a control of the charging voltage while taking into account the aging of gas discharge components (particularly of the work gas) without recalibration of the system.

Abstract: The ridge waveguide type photo semiconductor device includes: a first cladding layer of a first conductivity type formed on a semiconductor substrate of the first conductivity type; an active layer formed on the first cladding layer; a second cladding layer of a second conductivity type formed on the active layer; a third cladding layer of the second conductivity type formed on the second cladding layer and being worked so as to have a ridge shape; and an impurity diffusion region formed in the second cladding layer and the active layer on both sides of the ridge-shaped third cladding layer and which has a higher resistance value than that of the second cladding layer below the ridge shape.

Abstract: A lower multilayer reflection film (2), a light emitting layer forming portion (6) and an upper multilayer reflection film (8) are sequentially formed on a substrate (1) to form a semiconductor laminated portion (9), and a current injection region A is formed at a part of the semiconductor laminated portion so as to emit light from the surface in the center thereof. And, according to the present invention, the current injection region A is formed so as to be deflected from a center of the substrate. As a result, there is provided a surface light emitting type semiconductor laser capable of monitoring a light emitting power correctly and controlling it automatically in order to achieve the constant light emitting power in a case where the surface light emitting type laser chip is used as a light source for a pickup or the like.

Abstract: The present invention is a method and apparatus for using ring resonators to produce narrow linewidth hybrid semiconductor lasers. According to one embodiment of the present invention, the narrow linewidths are produced by combining the semiconductor gain chip with a narrow pass band external feedback element. The semi conductor laser is produced using a ring resonator which, combined with a Bragg grating, acts as the external feedback element. According to another embodiment of the present invention, the proposed integrated optics ring resonator is based on plasma enhanced chemical vapor deposition (PECVD) SiO2/SiON/SiO2 waveguide technology.

Abstract: The present invention relates to a laser apparatus comprising a laser light emitting optical system for emitting laser light to a surface, a power stabilizing system for stabilizing the laser light power with a predetermined power interval, and a deflection system for deflecting light reflected from the surface away from the power stabilizing system. Thereby, the power stabilizing system will not erroneously regulate the power due to reflections from the surface to be treated. Furthermore, the invention relates to a method for treating an animal, including a human being, for a laser light treatable disease using the laser apparatus on the skin or the mucosa of the animal and allowing laser light to be emitted from the laser light emitting optical system to the skin or mucosa.

Abstract: A laser system includes a pump source that produces a first output. The pump source has a feedback loop with a first summing junction and a first command that has step quantization or digitized set point. An output device is coupled to the pump source to receive the first output and produce a second output. A feedback loop is coupled to the first summing junction. The feedback loop includes a second summing junction coupled to at least a portion of the second output. The second summing junction receives a second command and provides an input to the first summing junction. The feedback loop reduces the step quantization from the first output to provide finer control step of a property of the second output.

Abstract: The invention includes an electrically pumped polycrystalline ZnO laser and it's fabrication procedure. A film of ZnO is grown on a suitably adapted polycrystalline underlayer in which the grains are surrounded by electrically insulating boundaries.

Abstract: Heretofore, if the beam size of the resonance mode is made small in a long resonator length, there arises a problem that the operation of the laser resonator becomes easy to be unstable and hence the adjustment thereof becomes difficult. A laser resonance includes: a laser material; a telescope for magnifying a laser beam which has been made incident from the laser material and for reducing a laser beam which has been made incident from the side opposite thereto; a flat reflecting mirror for reflecting the laser beam which has been made incident from said telescope; a telescope for magnifying the laser beam which has been reflected by the flat reflecting mirror to be reduced by the telescope and to be amplified by the laser material to be made incident thereto; and a flat reflecting mirror for reflecting the laser beam which has been made incident from the telescope.

Abstract: A laser illuminating apparatus that illuminates a linear or strip-shaped area (S) of sheet material (B) with high radiant power contains a diode laser (2) whose output is followed by two mutually orthogonally oriented rod lenses (4, 6) whose focal length is small in comparison to their distance. Between the two rod lenses (4, 6) a laser light beam fan (L2) is formed. Said fan is focused by the second rod lens (6) on a narrow linear area (S). Behind said area the laser beams diverge at a large angle (?) so that the power density decreases accordingly rapidly. If the light falls on the retina of an observer's eye, the laser light is not focused pointwise but only linearly, which excludes injury to the eye due to the accordingly low power density.

Abstract: The present invention provides a gas discharge ultraviolet laser capable of producing a high quality pulsed ultraviolet laser beam at pulse rates greater than 2000 Hz at pulse energies at 5 mJ or greater and having an enclosed beam path at least a portion of which comprises an oxidation agent. In a preferred embodiment a portion of the beam path comprises a sealed chamber containing a gas comprising a small concentration of oxygen. In one preferred embodiment the sealed chamber is an etalon chamber and the contained gas is nitrogen with an oxygen concentration of between 1.6 and 2.4 percent. In another preferred embodiments a small concentration of oxygen is added to the purge gas of a special purge compartment containing optical components exposed to high intensity output laser beam.

Abstract: A laser light source is equipped with a semiconductor light-emitting device, a first wavelength selector, and a second wavelength selector. The first and second wavelength selectors are used to select the wavelength of the light emitted from the light-emitting device, and constitute an external resonator. The semiconductor light-emitting device is provided with a stripe, which is formed oblique to the cleaved end facets of the light-emitting device that do not constitute the external resonator. The end facets of the semiconductor light-emitting device are provided with coatings, which become antireflective coatings with respect to the selected wavelength.

Abstract: The present invention relates to a cascaded multi-wavelength Raman fiber laser adapted for emitting radiation of at least one wavelength &lgr;s1, with a length of optical fiber (13) having input (15) and output (16) sections, means (11) for introducing pump radiation of wavelength &lgr;p into said length of optical fiber (13), at least one pair of spaced-apart reflector means (151,161; . . .

Abstract: A pumped-fiber laser comprising a multimode doped fiber (1) and a holographic spatial mode conversion device (3).

Abstract: A method for generating a long effective pulse duration output beam of laser radiation using a flashlamp-excited dye laser is described. A spaced series of excitation pulses is electronically generated using a pulse forming module. The series of excitation pulses are provided to a flashlamp-excited dye laser, which generates an output beam of laser radiation. The output beam is comprised of a series of spaced micropulses of laser radiation which, in combination, provide a long effective pulse duration.

Abstract: The present invention is directed to the development of compact, coherent sources emitting in the terahertz frequency region using interface phonons. In accordance with a preferred embodiment, a semiconductor heterostructure light emitting device includes a quantum cascade structure having at least an upper lasing level and a lower lasing level. The system uses heterostructure interface phonon bands to depopulate the lower lasing level of at least a three level semiconductor device. The device includes multiple coupled quantum well modules. In alternate preferred embodiments, the device includes quantum dot layers and/or, quantum wire structures, and/or mini-bands in a superlattice, for example, GaAs/AlGaAs superlattice. The phonons in the device improve efficiency, decrease the threshold current and result in system temperatures that are as high as room temperature. The semiconductor device provides emission of terahertz radiation.