Abstract: Resonant cavity diode, operating at the same wavelength for emission and detection of light. This diode is particularly applicable to telecommunications and comprises a resonant cavity (12) delimited by two mirrors (8, 16) and containing an active medium (14) and at least two insulating and coaxial rings (24, 30, 32) with the same inside diameter and the same outside diameter, the total thickness of the rings being provided such that the optical length of the resonant cavity is k×? (k?2), in the part of this cavity that passes through the rings, and is (k?1)×? in the part containing these rings, where ? is the wavelength at which the diode is capable of emitting and detecting.

Abstract: The present invention relates to a method for revising a wavelength of the EML by controlling a working temperature based on arithmetic functional relations between the DC-Offset voltage and the wavelength and between the working temperature and the wavelength, and a computer-readable recording medium thereof. The method includes the steps of: re-setting initial values of a working temperature, a amplifying voltage and the DC-Offset voltage; determining a wavelength with respect to the re-set DC-Offset voltage based on a functional relation between the DC-Offset voltage and the wavelength of the EML; and determining the revising working temperature for the determined wavelength based on the functional relation between the working temperature and the wavelength of the EML, and re-setting the working temperature with the revising working temperature.

Abstract: A semiconductor electrooptic monolithic component comprising successively a first section capable of emitting light at a first wavelength and including a first active layer, a second section capable of absorbing light at the said first wavelength and including a second active layer, and a third section capable of detecting light at a second wavelength and including a third active layer. The component is characterized in that the second active layer is designed to ensure in the said second section an absorption higher than that which would be allowed by an active layer identical to the said first layer.

Abstract: Incorporation of a GaAs “Extended lower barrier” in between quantum wells using nitrogen and confining layers using aluminum. Not to be confused with barrier layers used in quantum wells, the extended lower barrier is formed between the active region a nd the outer/confining layers where N and Al are respectively used. N and Al can be separated in the case where, for example, AlGaAs is being used in the confining layers and any nitrogen containing material is being used in the active region. Aluminum and Nitrogen when allowed to combine can cause deep traps and resultant non-radiative recombination, therefore N and Al pairing should be prevented. The GaAs extended barrier layer can provide a protective measure against such combination.

Abstract: An optical fiber laser has an output that is stabilized to adapt to changes in laser operating temperature. At the output of the laser a plurality of wavelength-selective stabilizing reflectors is provided, each having a reflectivity profile with a different center wavelength. The reflectors, typically Bragg gratings, have a relative degree of reflectivity and relative wavelength separation that results in the output power of the laser being at one or more of the reflector center wavelengths throughout the temperature change. Thus, as a temperature shift causes the wavelength of the optical energy generated in the laser gain medium to change, the grating-stabilized output of the laser shifts between one locked wavelength and another. However, the output remains stable over the extended wavelength range provided by the multiple reflectors. Such a laser is particularly useful in an amplifier system in which the laser is used as an optical pump source.

Abstract: A gas discharge laser crystallization apparatus and method for performing a transformation of a crystal makeup or orientation in the substrate of a workpiece is disclosed which may comprise, a multichamber laser system comprising, a first laser unit comprising, a first and second gas discharge chamber; each with a pair of elongated spaced apart opposing electrodes contained within the chamber, forming an elongated gas discharge region; a laser gas contained within the chamber comprising a halogen and a noble gas selected to produce laser light at a center wavelength optimized to the crystallization process to be earned out on the workpiece; a power supply module comprising, a DC power source; a first and a second pulse compression and voltage step up circuit connected to the DC power source and connected to the respective electrodes, comprising a multistage fractional step up transformer having a plurality of primary windings connected in series and a single secondary winding passing through each of the plura

Abstract: A laser transmitter includes an input stage generating an input signal to a limiting amplifier, the limiting amplifier generating an input signal to a laser driver, and the laser driver generating an input signal to a light source. The limiting amplifier has a control terminal for receiving a control signal that sets an amplitude characteristic of the input signal to the laser driver. The amplitude characteristic may be a common-mode or a peak amplitude of the input signal to the laser driver.

Abstract: The present invention provides an optical transmission module configured such that a driver IC chip to drive a semiconductor laser device, a first insulation plate having the semiconductor laser device mounted thereon and a coupling optical component are mounted in this order, a thin film inductor element and thin film resistor element which are connected in parallel are formed on a second insulation plate and a bias current is supplied to the semiconductor laser device via this LR element.

Abstract: A nitride semiconductor laser device of high reliability such that the width of contact between a p-side ohmic electrode and a p-type contact layer is precisely controlled. The device comprises a substrate, an n-type nitride semiconductor layer, an active layer, and a p-type nitride semiconductor layer. All the layers are formed in order on the substrate. A ridge part including the uppermost layer of the p-type nitride semiconductor layer of the p-type nitride semiconductor layer i.e., a p-type contact layer is formed in the p-type nitride semiconductor layer. A p-side ohmic electrode is formed on the p-type contact layer of the top of the ridge part. A first insulating film having an opening over the top of the ridge part covers the side of the ridge part and the portion near the side of the ridge part. The p-side ohmic electrode is in contact with the p-type contact layer through the opening. A second insulating film is formed on the first insulating film.

Abstract: A high-output semiconductor laser of a real index-guided structure comprises: a first conductive type clad layer; active layer for emitting light by current injection; second conductive type first clad layer; second conductive type second clad layer as a ridge waveguide; current-blocking layer formed in both sides of the second conductive type second clad layer and having a larger band gap than those of the second conductive type first and second clad layers; and second conductive type third clad layer having a mobility enough to guide a current to the second conductive type second clad layer and prevent a flow of a leak current into the current-blocking layer.

Abstract: Improved temperature stabilization can be obtained for pulsed gas discharge laser systems, such as excimer laser systems, using information about the energy dissipation of the system. Temperature sensors have a limited response time, which can lead to undesirable instability in gas temperature. By determining the heat energy provided to the discharge chamber over sufficiently small periods of time, a system controller can account for rapid variations in the temperature of the laser gas. The temperature regulation controller can adjust a flow of cooling liquid into the discharge chamber to account for these rapid variations on a scale that is much shorter than the response time of the temperature sensors. For variations over longer periods of time, the temperature regulation controller can utilize an active heater in contact with the laser tube to heat the laser tube body, thereby uniformly heating the gas in the tube.

Abstract: The invention relates to a method for checking the regulation state of a frequency-stabilised laser system comprising a laser (2). At least one first sidebrand frequency VHF is modulated to the laser beam (1) of said laser, the laser beam being guided through an absorption material (13) comprising a plurality of absorption lines in a detuning region of the laser (2), said absorption lines being arranged at different distances from each other. The laser frequency VL is detuned and, as a regulation signal for the laser frequency VL, it is determined whether there has been an absorption in the absorption material.

Abstract: Pulse parameters of a gas discharge laser system can be optimized and controlled for precision applications such as microlithography. Important laser pulse parameters typically vary in the beginning of a pulse burst, and the directionality of the output beam typically varies throughout the burst. In order to improve the performance of the laser system, the variation at the beginning of a pulse burst can be eliminated by extending the pulse pattern and shuttering the output during periods of significant parameter variation. A fast shutter such as an acousto-optical modulator can be used to prevent output during the burst transition processes. Elements such as acousto-optical cells also can be used in combination with a fast position sensor to steer the direction of the output beam, in order to adjust for variations in the direction of the beam between pulses in a burst.

Abstract: The present invention provides quantum cascade lasers and amplifier that operate in a frequency range of about 1 Terahertz to about 10 Terahertz. In one aspect, a quantum cascade laser of the invention includes a semiconductor heterostructure that provides a plurality of lasing modules connected in series. Each lasing module includes a plurality of quantum well structure that collectively generate at least an upper lasing state, a lower lasing state, and a relaxation state such that the upper and the lower lasing states are separated by an energy corresponding to an optical frequency in a range of about 1 to about 10 Terahertz. The lower lasing state is selectively depopulated via resonant LO-phonon scattering of electrons into the relaxation state.

Abstract: An optical element module package with a TO-can structure is disclosed. The module includes a laser diode for projecting optical signals and a photo diode for monitoring the optical signals projected from the laser diode. The package includes a stem having a first through-hole formed in a long-hole shape parallel to the diametrical direction of the stem, the first through-hole extending through the stem from one side to the other; and a plurality of leads arranged in a row through the first through-hole. The first through-hole is filled with a sealant of a glass material so that the stem and the leads are fixed.

Abstract: A gas laser oscillator of easy maintenance which is capable of switching a beam mode at high speed. Electric discharge sections in which gas medium is flown are formed in an optical resonating space in an electric discharge tube between a rear mirror and an output mirror. Electrodes are connected to electric discharge power sources (alternating current or direct current power sources). Coils are wound around the electric discharge tube at the respective electric discharge sections and excited by coil excitation circuits. Directions and intensities of the excitation currents from the coil excitation circuits are controlled by a controller. Regions in which the electric discharge currents flow between the electrodes in the respective electric discharge sections are varied by magnetic fields generated by the coils in accordance with the directions and intensities of the excitation currents of the coils, to thereby control the beam mode.

Abstract: A chemical oxygen-iodine laser (COIL) comprises an oxygen generator and a nozzle for accelerating generated oxygen to a high or supersonic velocity. A laser cavity is coupled to the nozzle, wherein the accelerated fluid, with injected iodine, is employed as a laser gain medium. A Brayton cycle outlet pump employs the accelerated oxygen and iodine as a component of a process fluid in a Brayton cycle to raise the static pressure of the accelerated fluid to ambient conditions. The Brayton cycle pump comprises a compressor having an inlet and an outlet, the inlet being coupled to the laser cavity to receive and compress accelerated oxygen. A combustor is coupled to the outlet of the compressor to receive compressed oxygen and ignite and combust it A turbine is coupled to the outlet of the combustor to expand the ignited and combusted gas, wherein the turbine powers the compressor. Multiple reheat stages may be used and regeneration and intercooling may also be used.

Abstract: Apparatus/method providing bandwidth control in narrow band short pulse duration gas discharge laser output light pulse beam producing systems, producing a beam comprising pulses at selected pulse repetition races, e.g., comprising a dispersive bandwidth selection optic selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the beam containing the respective pulse on the optic; a tuning mechanism operative to select at least one angle of incidence of the beam containing the respective pulse upon the optic; the tuning mechanism comprising a plurality of incidence angle selection elements each defining an angle of incidence for a different spatially separated but not temporally separated portion of the pulse to return from the optic a laser light pulse comprising a plurality of spatially separated but not temporally separated portions, each having one of at least two different selected center wavelengths.

Abstract: Submount substrates are connected to both sides of a laser diode via hard solders. The lower submount substrate and a heat sink are connected together by a soft solder. The heat sink and a presser electrode are fixed with a predetermined gap therebetween via an insulating spacer. A coil electrode is fitted in a V-shaped groove of the presser electrode. As the coil electrode is deformed slightly elastically, the coil electrode is pressed against the upper submount substrate.

Abstract: A device for emission of light is made including an emitting structure including an active part and a micro-cavity, delimited by mirrors and containing the active part, and a laser diode designed for pumping the emitting structure. The emitting structure is fixed to the laser diode. The device is particularly applicable to the detection of gas.