Abstract: The laser includes a resonant cavity formed between a first mirror and a second mirror. An unsensitized Erbium-doped crystal gain medium for producing laser gain is disposed within the resonant cavity. A saturable absorber is disposed within the resonant cavity. A pump source is positioned to energize the gain medium. The saturable absorber, the laser gain, the resonator length, and the second mirror being selected so that output pulses having a duration of less than 75 nanoseconds are generated by the laser.

Abstract: A method and apparatus for temperature stabilization of a wavelength of a laser compensate for thermal instability of a internal etalon of the wavelength using the results of measuring the wavelength with an external wavelength meter.

Abstract: A laser beam source has a laser element provided with a thin crystal disk as a laser active medium. The laser beam source has improved mechanical stability and improved thermal contact with respect to a cooling element on the flat side of the crystal disk that is disposed opposite the cooling element. A cooling disk is disposed between the crystal disk and the cooling element.

Abstract: A 780 nm band semiconductor laser device has an InGaAsP well layer, phosphorous composition of which is 0.51 smaller than 0.55 to prevent spinodal decomposition in growing InGaAsP. A compressive strain of 0.65% less than 1% and more than 0.25% is introduced into the well layer to reduce threshold current thereof. Thus, the 0.78-?m band semiconductor laser device having the InGaAsP well layer stably operates for a long time even in outputting a high optical power of 100 mW or more. A tensile strain of 1.2% is also introduced into barrier layers within the active region so as to compensate the stress due to the compressive strain of the well layer. As a result, the reliability of the semiconductor laser device is further increased during a high output operation.

Abstract: A diode-pumped solid-state laser including a short wavelength (e.g., blue, violet, or UV) semiconductor laser that pumps an absorption transition in a rare-earth-doped material. Responsive to this pumping, the rare-earth active ion directly emits laser radiation. A number of different wavelength outputs, including short wavelengths, are achievable dependent upon the material and the pump wavelength. The gain medium may include an active ion selected from Er3+ Sm3+, Eu3+, Tb3+, Dy3+, Tm3+, Ho3+, and Pr3+. A laser diode pump source has a wavelength in the range of about 365 nm to 480 nm to excite a laser emission in the range of 370 to 800 nm. The laser diode pump source may comprise a GaN-based semiconductor. In some embodiments, the laser diode pump source supplies a pump beam in a range of 370–380 nm, 400–415 nm, 435–445 nm, or 468–478 nm.

Abstract: The width of a current pass region of a semiconductor laser device is narrowed as much as possible, thus implementing a stable single transverse mode. The device is relatively resistant against physical impact. The device includes a semiconductor substrate having first and second opposite surfaces, and, in order, a first conductive type clad, active layer, etch stop layer, current blocking layer formed in a V-groove shape so that a part of the etch stop layer is exposed, second conductive type clad formed entirely over the entire of the V-groove and the current blocking layer, optical guide layer, current pass facilitation layer, cap layer, second conductive type electrode, and a first conductive type electrode formed on the second surface of the semiconductor substrate.

Abstract: Systems and methods for biasing an externally modulated laser. An inductorless bias T network is provided that includes a terminating resistor in series with a capacitor. The capacitor is an open circuit for a bias signal and a virtual ground for an RF signal. Thus, the RF signal is terminated by the terminating resistor without dissipating the bias signal through a ground return path of the RF signal. Using a charge pump inverter, a positive supply can be used to positively bias a laser and negatively bias the external modulator through the terminating resistor. A negative power supply is not required. A swing voltage provided by the RF signal causes the external modulator to modulate the light emitted by the laser.

Abstract: A laser package includes a submount, a laser die mounted on the submount, a lid mounted on the submount over the laser die, and a soft metal disposed between the laser die and the lid, wherein the soft metal conducts heat between the laser die and the lid. The soft metal is able to creep or cold flow under pressure to accommodate for varying manufacturing tolerances and varying thermal expansion rates of the elements in the laser package.

Abstract: A beam delivery unit and method of delivering a laser beam from a laser light source for excimer or molecular fluorine gas discharge laser systems in the DUV and smaller wavelengths is disclosed, which may comprise: a beam delivery enclosure defining an output laser light pulse beam delivery pat from an output of a gas discharge laser to an input of a working apparatus employing the light contained in the output laser light pulse beam; a purge mechanism operatively connected to the beam delivery enclosure; an in-situ beam parameter monitor and adjustment mechanism within the enclosure, comprising a retractable bean redirecting optic; a beam analysis mechanism external to the enclosure; and, a retraction mechanism within the enclosure and operable from outside the enclosure and operative to move the retractable beam redirecting optic from a retracted position out of the beam path to an operative position in the beam path.

Abstract: A ridge waveguide semiconductor laser includes an active layer, semiconductor layers on the active layer and having a ridge-shaped waveguide, an insulating film on the semiconductor layer, a first electrode layer in contact with the semiconductor layer through an opening in the insulating film, and a second electrode layer on the first electrode layer having a stripe shape and extending along the waveguide. A distance from an end face of a resonator of the laser to an edge of the second electrode layer does not exceed 20 ?m.

Abstract: Disclosed is a method for maintaining wavelength-locking of a Fabry-Perot laser regardless of a change of external temperature even though a temperature controller is not used, and a wavelength division multiplexing (WDM) light source using the method, as an economical light source used in a WDM optical communication field. The WDM light source comprises a Fabry-Perot laser for injecting spectrum-spliced incoherent light to amplify and output only an oscillation mode matching with a wavelength of the injected light, and a bias controlling unit for adjusting a bias current supplied to the Fabry-Perot laser to a value adjacent to a threshold current of the Fabry-Perot laser, whose threshold current is changed according to a temperature and a relationship between the injected light changed depending to a temperature and a wavelength of the oscillation mode.

Abstract: Provided is a diode-pumped solid-state laser adapted for an intracavity sum-frequency mixing for generating a laser radiation of a visible wavelength range by performing a sum-frequency mixing of two laser inputs in a laser resonant cavity. A pair of laser resonators of two different wavelengths are formed along a common optical path and an intracavity sum-frequency mixing is conducted so as to obtain a laser radiation at a sum-frequency wavelength by placing a nonlinear optical crystal on this common optical path. By suitably selecting the properties of the reflective surfaces that form the laser resonators, a laser radiation of a relatively short wavelength range can be obtained even though the wavelength of the pumping laser beam is relatively long, and an extremely high conversion efficiency can be achieved.

Abstract: To provide a surface-emitting light emitting device including an optical member whose mounting position, form, and size have been favorably controlled, and a method of manufacturing the same, as well as an optical module and an optical transmission apparatus that include this surface-emitting light emitting device, the surface-emitting light emitting device of the present invention can emit light perpendicular to a substrate and includes an emitting surface that emits the light, a base member that is provided on the emitting surface, and an optical member that is provided on an upper surface of the base member.

Abstract: A laser driver circuit for reducing electromagnetic interference is disclosed. The laser driver circuit includes a first differential amplifier circuit, a second differential amplifier circuit and a glitch smoothing circuit. The first differential amplifier circuit is coupled to a pair of differential input signals, and is configured to generate a first amplified signal. The second differential amplifier circuit is coupled to the pair of differential input signals, and is configured to generate a second amplified signal. The first and second amplified signals together form a differential pair of output signals. The glitch smoothing circuit has a first output terminal coupled to the first differential amplifier circuit and a second output terminal coupled to the second differential amplifier circuit. The glitch smoothing circuit is configured to reduce glitches on the differential pair of output signals when the pair of differential input signals switch states.

Abstract: A monolithically formed laser and photodiode. The monolithically formed laser and photodiode includes a Vertical Cavity Surface Emitting Laser (VCSEL) that includes a first PN junction. The first PN junction includes a first p layer and a first n layer. A tunnel diode is connected to the VCSEL both physically and electronically through a wafer fabrication process. A photodiode is connected to the tunnel diode. The photodiode is connected to the tunnel diode by physical and electronic connections. The tunnel diode and photodiode may share some common layers. The tunnel diode includes a second PN junction. The monolithically formed laser and photodiode allow for an integrated structure with diode biasing flexibility including the use of a single supply to bias both the laser and photodiodes.

Abstract: A method of operating a laser to obtain an output pulse having a single wavelength, comprises inducing an intracavity loss into a laser resonator having an amount that prevents oscillation during a time that energy from the pump source is being stored in the gain medium. Gain is built up in the gain medium with energy from the pump source until formation of a single-frequency relaxation oscillation pulse in the resonator. Upon detection of the onset of the relaxation oscillation pulse, the intracavity loss is reduced, such as by Q-switching, so that the built-up gain stored in the gain medium is output from the resonator in the form of an output pulse at a single frequency. An electronically controllable output coupler is controlled to affect output pulse characteristics. The laser acts a master oscillator in a master oscillator power amplifier configuration. The laser is used for laser peening.

Abstract: External-cavity optically-pumped semiconductor lasers (OPS-lasers) including an OPS-structure having a mirror-structure surmounted by a surface-emitting, semiconductor multilayer (periodic) gain-structure are disclosed. The gain-structure is pumped by light from diode-lasers. The OPS-lasers can provide fundamental laser output-power of about two Watts (2.0 W) or greater. Intracavity frequency-converted arrangements of the OPS-lasers can provide harmonic laser output-power of about one-hundred milliwatts (100 mW) or greater, even at wavelengths in the ultraviolet region of the electromagnetic spectrum. These high output powers can be provided even in single axial-mode operation.

Abstract: A light confinement layer constructed of a semiconductor that has a refractive index different from that of p-type second cladding layers is formed to a small film thickness of not greater than 2 ?m (about 0.5 ?m) on the whole surface of ridge portions of two semiconductor lasers. Thus, the light confinement layer on the ridge portions is made roughly flat so as to be easily removable by etching. As a result, the exposure of p-type second cladding layers of the ridge portions due to deep etching is prevented to allow the confinement of light into the p-type cladding layers to be stably effected. A dielectric film is formed on the light confinement layer and reinforces the current constriction function lost by the reduction in the thickness of the light confinement layer.

Abstract: A system and method is disclosed for improving the safety of directionally sensitive medical and industrial applications, such as laser applications, and cutting or surfacing tools. A system of electromagnetic radiation safety beam emitters and detectors is used to prevent a user from directing or positioning an application device, such as an electromagnetic beam source or high-power water jet, to areas outside a predefined application area and also to prevent operation of an application beam should persons or objects intersect a security boundary. In a first preferred embodiment, one or more safety beam emitters are placed in or near a treatment area, and a “safety beam” produced by the emitter is preferably directed toward the preferred position of the source of the application beam. In a second preferred embodiment, the safety beam emitter(s) is directed toward the application area of the source, and the detectors detect radiation reflected from the application area.

Abstract: The present invention provides a light emitting device drive circuit which does not require complicated feedback control for shortening a rising response delay time in the transition from an extinction state of a light emitting device to a light emitting state so as not to increase a bias current, and for eliminating harmful effects due to the influence of a droop phenomenon. A circuit including a series of a coil 55 and a resistor 54 is connected in parallel with an LD 53. In this configuration, the LD 53 is subjected to supply of an overshoot drive current ILD for a time period determined by a time constant of the coil 55 and the resistor 54, i.e., a time period in which a high-frequency current is supplied in the transition from the extinction state to the light emitting state. Thus, a delay in rise time until light emission of the LD 53 can be decreased.