Abstract: A high-output semiconductor laser element includes a plurality of laser structures which are superposed on a substrate one on another with a P+N+-tunnel junction intervening between each pair of the laser structures. Each of the laser structures includes at least one active layer interposed between a P-type clad layer and a N-type clad layer. The active region of each of the laser structures is not smaller than 10 &mgr;m and not larger than 80 &mgr;m in width. The distance h between the active layers which are most distant from each other in the active layers of the laser structures is not larger than the width W of the active region which is the widest in the laser structures. The width of said semiconductor laser element is not smaller than W+2h.

Abstract: Two semiconductor laser light sources for outputting light of two properly selected wavelengths are employed as excitation light sources. That is, as excitation light sources, there are used a first semiconductor laser excitation light source for exciting ion from a base level to a laser low level or an energy level higher than the laser low level and a second semiconductor laser excitation light source having a wavelength different from that of the first excitation light source for exciting ion from a laser low level to a laser high level. For example, an amplification fiber uses a fluoro zircon ate glass as a base material. Two multiple wavelength couplers are disposed at the input side of the amplification fiber. The multiple wavelength couplers are connected to the first excitation light source and the second excitation light source, respectively.

Abstract: The present invention provides a modular high repetition rate ultraviolet gas discharge laser light source for a production line machine. The system includes an enclosed and purged beam path for delivery the laser beam to a desired location such as the entrance port of the production line machine. In preferred embodiments, the production line machine is a lithography machine and two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber. This MOPA system is capable of output pulse energies approximately double the comparable single chamber laser system with greatly improved beam quality. A pulse stretcher more than doubles the output pulse length resulting in a reduction in pulse power (mJ/ns) as compared to prior art laser systems.

Abstract: In a semiconductor laser element: an n-type cladding layer, an undoped or n-type optical waveguide layer, an Inx3Ga1-x3As1-y3Py3 quantum-well active layer, and an undoped or p-type optical waveguide layer are formed on an n-type GaAs substrate; a first etching stop layer and an n-type first current confinement layer are formed corresponding to high-refractive-index regions realizing an ARROW structure; a second etching stop layer and an n-type second current confinement layer are formed with an opening for current injection; and a p-type cladding layer and a p-type GaAs contact layer are formed over the entire upper surface. For example, the compositions of the cladding layers, the optical waveguide layers, the first etching stop layer, the first current confinement layer, the second etching stop layer, and the second current confinement layer are In0.49Ga0.51P (or Alz1Ga1-z1As), GaAs, p-type Inx8Ga1-x8P, GaAs, n-type or p-type Inx8Ga1-x8P, and Alz1Ga1-z1As, respectively.

Abstract: An improved electrical contact structure can be manufactured by plating a component of a first material such as molybdenum with a second material such as copper or silver. The first and second materials are selected to provide a desired effective coefficient of thermal expansion (CTE) and electrical conductivity. The contact structure can be made very thin for implementations in which multiple lasers are to be stacked closely together. The manufacturing processing can be carried out very inexpensively by first etching the outline of multiple components in a sheet of the first material and then plating the etched sheet with the second material.

Abstract: The invention is directed to a compact optically side-pumped solid-state laser with an optimized overlap between the mode of the laser beam propagating in the laser material and the pump beam. Using a common pump volume, the compact solid-state laser can simultaneously emit laser beams at different wavelengths. The laser can be combined with nonlinear optical elements to provide a RGB three color laser architecture suitable for color projection display applications.

Abstract: A method and apparatus for cooling a high power laser oscillator or amplifier is disclosed in which a plurality of laser gain media that are configured such that the width of the media is greater than the thickness of the media, are sandwiched between pairs of optically transparent materials having high thermal conductivity. In this way, a shortened thermal path is created from the face surface of the laser gain media axially via the optically transparent heat conductor to an external heat exchange system. This provides an increased level of cooling of the interior of the laser gain media and avoids the deleterious effects caused by over heating of the laser gain media particularly with large effective cross sections desired for high power and/or high pulse repetition and high pulse energy operation.

Abstract: A laser assembly includes an epitaxial structure formed on a substrate. A separately controllable tunable laser resonator and external optical amplifier are formed in the epitaxial structure. At least a portion of the laser and amplifier share a common waveguide, which may have non-uniform optical or geometrical properties along the waveguide centerline or across a normal to the centerline.

Abstract: An optical semiconductor diode driver circuit, which is stably operable even with the supply of a source voltage slightly higher than the forward operation voltage of an optical semiconductor diode to be driven and can output switch current and voltage sufficient for driving the optical semiconductor diode, includes a pre-driver circuit operating as a limiting amplifier, and an output circuit responsive to a pulse-shaped voltage output from the pre-driver circuit and outputting a drive pulse current to the optical semiconductor diode as an external load. The output circuit is basically a type of the emitter-coupled amplifier which has either a differential configuration or a similar one to a Schmitt circuit and whose common-emitter loads are composed of a resistor and a variable constant current source to determine a amplitude of the output current pulse with small rise and fall times.

Abstract: The invention relates to a device and method for tuning the wavelength of the light in an external cavity laser. The external cavity laser comprises an optically amplifying semiconductor chip, a first reflecting surface, an Anti-Reflection (AR) coated semiconductor chip facet, a diffraction grating on which at least part of the beam originating from the AR coated semiconductor chip facet is incident and diffracted back to the optically amplifying semiconductor chip, means for collimating the light emitted from the AR coated semiconductor chip facet towards the diffraction grating, and a movable part. By the movement of the moveable part, the wavelength of the light can be turned in the external cavity laser. The movable part of the external cavity laser exhibits a rotational movement relative to the optical axis of the external movement being actuated by an electrodynamic force generated within an integral section of the moveable part.

Abstract: A surface emitting laser and a surface emitting laser array capable of high-luminance optical output in fundamental transverse mode, which can be produced easily with good reproducibility and with small position variation. The surface emitting laser has an active layer region composed of an active layer and upper and lower spacer layers deposited on both sides thereof and reflection layers deposited on both sides of the active layer region, an upper reflecting layer deposited on the upper spacer layer of the active layer region, a lower reflecting layer deposited on the lower spacer layer of the active layer region, and a secondary cavity formed by a first mode control layer and a second mode control layer placed on the periphery of the region of emission of the laser beam at the upper reflecting layer.

Abstract: A wavelength converter assembly includes a substrate. An epitaxial structure is formed on the substrate with areas of different optical properties. A laser and a photodetector are formed in the epitaxial structure. The photodetector generates a first electrical signal in response to an optical signal. A conditioning circuit is coupled to the laser and the photodetector. The conditioning circuit receives the first electrical signal and provides a second electrical signal to the laser to modulate its optical output.

Abstract: The laser guidance assembly (20) includes a platform (26) supported on a vehicle. A mirror support (24) is rotatably supported by the platform (26) for rotation about a vertical axis. A first mirror (22) is supported by the mirror support (24) for rotation about the vertical axis. The assembly (20) further includes a diode (30) attached to the platform (26) for emitting a laser beam (32) in a laser path (34). The assembly (20) is characterized by having a pivotal connection (36) between the first mirror (22) and the mirror support (24) for allowing oscillation of the first mirror (22) about a horizontal axis (48) relative to the platform (26) and the mirror support (24). The assembly (20) has a second mirror (38) supported by the platform (26) and fixed relative to the platform (26) for reflecting a reflected laser beam (40) from the first mirror (22).

Abstract: An apparatus designed to prevent, by adjusting a flow of laser gas, discharge products from stagnating and being released again into a main discharge space, maintain the purity of the laser gas in the main discharge space, and stabilize the main discharge so as to minimize laser output fluctuation, in which conductors are interposed in the gaps between a main discharge electrode and a pair of corona preliminary ionization electrodes, from the upper surface of a support plate to the discharge starting points.

Abstract: A laser beam emitting device includes a laser diode, a drive current supply circuit, a laser power detection circuit, a first differential amplifier that outputs a first differential signal corresponding to a difference between the laser power detection signal and a reference value. A laser diode deterioration detection circuit includes a biasing circuit that modifies the laser power detection signal or the reference value upon issuance of deterioration detection command. A sample-hold circuit samples and holds the first differential signal just before the deterioration detection command is issued. A second differential amplifier outputs a second differential signal corresponding to a difference between the first differential signal after the deterioration detection command is issued and the signal held by said sample-hold circuit.

Abstract: Xenon gas is added from a small-sized Xe gas cylinder (15) to the excimer laser gas inside a chamber (10) supplied from an Ar/Ne gas cylinder (13) and an Ar/Ne/F2 gas cylinder (14), the xenon gas proportion is detected by an Xe gas sensor (16), and the supply of the xenon gas supplied to the chamber (10) from the Xe gas cylinder (15) is controlled by a gas controller (18).

Abstract: In a surface-emitting laser device, an Al0.16Ga0.84As cladding layer, a GaAs optical waveguide layer, an Al0.30Ga0.70As carrier block layer, a GaAs side barrier layer, an InGaAs active layer, a GaAs side barrier layer, an Al0.30Ga0.70As carrier block layer, a GaAs optical waveguide layer, an Al0.16Ga0.84As cladding layer, an etching stop layer, and a contact layer are formed on a GaAs substrate in this sequence. A inclined facet which functions as a reflecting mirror is formed on a resonator optical axis between a horizontal resonator facet and a vertical resonator facet. With the constitution, thermal saturation and facet degradation can be suppressed as much as possible and high optical output power can be obtained.

Abstract: A striped region with a convex cross section is formed as a laser resonant cavity on an n-type InP substrate. The lower part of the striped region includes an n-type InP cladding layer and an n-type InGaAsP first waveguide layer, which are stacked in this order on the substrate. The upper part of the striped region includes an InGaAsP active layer, a p-type InGaAsP second waveguide layer and a p-type InP cladding layer, which are stacked in this order on the first waveguide layer. The striped region extends along the zone axis, or in the [011] direction. The sides of the upper striped region have a crystallographic plane orientation (0-11), while the sides of the lower striped region have a crystallographic plane orientation (1-11)B.

Abstract: A distributed feedback semiconductor laser of the present invention includes a waveguide with an active layer and a diffraction grating, and a first phase shift region formed in the waveguide. The waveguide extends along a cavity-axial direction and is defined such that propagation of light in two different polarization modes is permitted in the waveguide. The first phase shift region extends along the cavity-axial direction and has a polarization dependency that an effective refractive index for propagation light of the first phase shift region differs from an effective refractive index for propagation light of a region of the waveguide other than the first phase shift region such that a phase shift of a quarter wavelength of the propagation light is created for one of the two polarization modes and a phase shift of a half wavelength of the propagation light is created for the other of the two polarization modes in the first phase shift region.

Abstract: A semiconductor laser of present invention is constructed by an aluminum oxide (Al2O3) film on an end surface opposed to a beam emission surface of the semiconductor laser, a silicon nitride (SiNx, or Si3N4) film on the aluminum oxide film, and a silicon oxide (SiO2) film on the silicon nitride film. These films are made successively by a method of Electron Cyclotron Resonance (ECR) sputtering.