Abstract: Feedback timing control equipment and process for an injection seeded modular gas discharge laser. A preferred embodiment is a system capable of producing high quality pulsed laser beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 to 10 mJ or greater for integrated outputs of about 20 to 40 Watts or greater. The feedback timing control is programmed to permit in some circumstances discharges timed so that no significant laser energy is output from the system. Use of this technique permits burst mode operation in which the first discharge of a burst is a no-output discharge so that timing parameters for each of the two chambers can be monitored before the first laser output pulse of the burst. 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.

Abstract: An electro-optic device for use with a laser beam. A crystal has a first face and a second face. Means are provided for applying a voltage across the crystal to obtain a net phase retardation on the polarization of the laser beam when the laser beam is passed through the crystal. In one embodiment the crystal is composed of a compound having the chemical formula ReAe40(BO3)3 where: RE consists of one or more of the following elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and two other elements Y and Sc; and where Ae is from the list of Ca, Sr, or Ba.

Abstract: A laser discharge unit is provided. The discharge unit includes an elongated electrode plate, an elongated high voltage electrode, and an elongated ground electrode. Both the high voltage electrode and the ground electrode are mounted to the electrode plate in a spaced-apart relationship with their longitudinal axis being substantially parallel to thereby define a gas discharge gap between the electrodes. The gas laser discharge unit may be removably mounted as a module into a gas laser such as an excimer laser.

Abstract: A gas laser comprises a pair of elongated electrodes arranged to define a discharge region between two opposing surfaces of said elongated electrodes, wherein the discharge region defines a longitudinal axis, a wide axis and a narrow axis. The gas laser further includes a lasing gas disposed in said discharge region and an excitation means for energizing the electrodes to excite the lasing gas. A first mirror is arranged in front of a first end of the pair of elongated electrodes, wherein the first mirror is spaced apart from the first end along the longitudinal axis by a first distance, and a second mirror is arranged in front of a second end of the pair of elongated electrodes. Moreover, the two opposing electrode surfaces define an electrode curvature, respectively, that is adapted such that a wave front of the a fundamental transverse radiation mode with respect to the narrow axis substantially coincides with a mirror curvature of the first mirror at the first distance.

Abstract: An electronic/photonic integrated circuit in which grating-outcoupled surface-emitting lasers are used both to provide external emission out of the plane of the chip (through gratings), and also to feed optical power into photonic waveguides parallel to the plane of the chip. Transistors are fabricated in a common multilayer semiconductor body with the lasers.

Abstract: A low clad layer made of semiconductor of a first conductivity type is formed on a semiconductor substrate. An active layer is formed on the low clad layer. The active layer is constituted by alternately stacking a strained well layer and a barrier layer. A partial or whole thickness of the active layer is periodically removed along a first direction parallel to the surface of the semiconductor substrate to form a diffraction grating. A filler made of semiconductor is embedded in the removed region. Strain of the strained well layer and strain of the filler have the same sign. An upper clad layer is formed on the active layer and filler and made of semiconductor of a second conductivity type. A semiconductor laser device is provided which has a smaller shift of spontaneous emission or PL even if a diffraction grating is formed in an active layer.

Abstract: A light source device for pumping a solid-state laser medium of a laser generator, which is compact and capable of economically using LD bars constituting the LD stack with easy maintenance. The light source device is constituted by a plurality of LD modules. Each LD module comprises a plurality of cooling devices on which LD bars are respectively mounted and connection plates on both sides thereof. The LD bars are stacked such that longitudinal directions thereof extend perpendicular to a stacking direction thereof. A desired number of LD modules are mechanically connected with each other using the connection plates to form the LD stack. A sealing member is intervened between confronting connection plates of adjacent LD modules, so that flow passages of coolant formed in the respective LD modules are continuously connected. The connection plates have functions of fixedly supporting the cooling devices of each LD module and electrically connecting the adjacent LD modules.

Abstract: A semiconductor laser device emitting a laser beam having stable emitting wavelength and a multimode spectrum is provided. The semiconductor laser device is a Fabry-Perot type semiconductor laser device having a layer structure including an active layer of a quantum well structure, and emitting a laser beam having wavelength stabilized by an action of return light and having a multimode spectrum, wherein each well layer satisfies relation: ?/d?1.3×10?3 nm?1 where ? and d(nm) are an optical confinement factor and a thickness of a well layer, respectively.

Abstract: In a short-wavelength laser module, long-term reliability is lost because of unnecessary gas deposited on the end face of its optical waveguide. A short-wavelength laser module has a package structure wherein a package lid used when the short-wavelength laser module is hermetically sealed does not make contact with internal gas, and a process of accelerating the polymerization of a securing agent used inside the package is incorporated, whereby unnecessary gas from the securing agent is eliminated and the long-term reliability of the output is attained.

Abstract: Normal incidence stack architecture coupled with the development of diode array pumping enables the power/energy per disk to be increased, a reduction in beam distortions by orders of magnitude, a beam propagation no longer restricted to only one direction of polarization, and the laser becomes so much more amendable to robust packaging.

Abstract: A laser array and method of making same has precision fiducial marks that aid in the alignment of the laser array. The invention requires forming additional optical features adjacent to the laser array that is used to write fiducial marks on an opposite surface in the medium containing the laser array. Fiducial marks are formed when high intensity collimated beams of light are directed through the optical features onto a treated portion of the transparent medium. Fiducial accuracies of 1 micron are possible by using this approach.

Abstract: A surface emitting semiconductor laser device including a substrate, a bottom DBR, and a mesa post having a layer structure, the layer structure including a top DBR including a plurality of pairs, each of said pairs including an Al-containing high-reflectivity layer and an Al-containing low-reflectivity layer, an active layer structure sandwiched between the DBRs for emitting laser, and a current confinement layer disposed within or in a vicinity of one of the DBRs, the current confinement layer including a central current injection area and an annular current blocking area encircling the central current injection area, the annular current blocking area being formed by selective oxidation of Al in an AlxGa1?xAs layer (0.95?x<1) having a thickness below 60 nm, the Al-containing low-reflectivity layer including Al at an atomic ratio not more than 0.8 and below 0.9.

Abstract: High-efficiency laser-like emission at low thresholds in dipolar organic materials upon pulsed optical excitation, without using any external mirrors. Unusually high conversion efficiencies and low thresholds in laser-like emission have been observed in the solutions of organic molecular salts having large dipole moments and specific dye molecules having high photoluminescence efficiencies. Pumped with frequency-doubled pulses from a Nd:YAG laser, conversion efficiencies in the range of 15-40% were achieved without incorporation of external mirrors. The threshold pump energies for such emission have been observed to be low (<8 ?J). The spectrally narrowed output beam was found to have low divergence, high degree of polarization, and pulse-width less than that of the excitation pulses (50 picoseconds).

Abstract: A dithering signal is superimposed on a laser frequency control signal. In this way, laser frequency control may be achieved by employing measurements from a single photodetector. By sampling synchronously to the dithering signal, it is possible to generate both the magnitude end sign of the current frequency error based on the output of a single photodetector. This reduces the number of components required to generate an optical signal and is particularly advantageous in WDM systems where laser frequency control components may be duplicated over a large number of channels.

Abstract: A semiconductor laser chip has a semiconductor laser element and a beam shaper integrated into the semiconductor laser chip and serving for shaping a laser beam emitted by the semiconductor laser element.

Abstract: The average power output of a laser is scaled, to first order, by increasing the transverse dimension of the gain medium while increasing the thickness of an index matched light guide proportionately. Strategic facets cut at the edges of the laminated gain medium provide a method by which the pump light introduced through edges of the composite structure is trapped and passes through the gain medium repeatedly. Spontaneous emission escapes the laser volume via these facets. A multi-faceted disk geometry with grooves cut into the thickness of the gain medium is optimized to passively reject spontaneous emission generated within the laser material, which would otherwise be trapped and amplified within the high index composite disk. Such geometry allows the useful size of the laser aperture to be increased, enabling the average laser output power to be scaled.

Abstract: Light from a first excitation light source is incident on one facet of a first optical fiber. A core is doped with a first rare earth substance. A resonant section induces light resonance in the core to generate resonant light, thereby providing selected light at the other facet of the first optical fiber. An optical multi/demultiplexer reflects the light of the selected wavelength in a direction different from that of the first optical fiber. A second excitation light source supplies light to the resonant section of the first optical fiber via the optical multi/demultiplexer and the other facet of the first optical fiber. A second optical fiber guides the light of the selected wavelength from the optical multi/demultiplexer to an exterior.

Abstract: A single-transverse-mode laser has a resonance cavity with an output end. A gain medium is disposed within the resonance cavity. The gain medium portion includes an active portion. A mode expander portion is disposed within the resonance cavity and operationally coupled to the gain medium portion and the output end of the resonance cavity. A single-mode waveguide portion is disposed with the resonance cavity between and operationally coupled to the mode expander portion of the output end of the resonance cavity. The single-mode waveguide portion is a passive portion. The gain medium portion, the mode expander portion and the single-mode waveguide portion are integrally formed.

Abstract: A vertical cavity surface emitting laser (VCSEL) using photonic crystals. Photonic crystals are formed such that the active region of the VCSEL is bounded by the photonic crystals. The photonic crystals have a periodic cavity structure that reflects light of certain wavelengths through the active region of the VCSEL such that laser light at the wavelengths is generated. Additional photonic crystals can be formed to increase the bandwidth of the VCSEL. The photonic crystals can also be combined with distributed bragg reflector layers to form the mirrors of a VCSEL.

Abstract: An SCH laser device fabricated in the (Al,Ga,In)P system has an active region disposed within an optical guiding region. The optical guiding region is disposed between an n-doped cladding region and a p-doped cladding region. The laser device is provided with optical confinement layers, which are disposed at the interfaces between the optical guiding region and the cladding regions. The optical confinement regions produce increased confinement of the optical field, and reduce the penetration of the optical field into the cladding regions. The optical confinement region on the p-side of the device also serves as a potential barrier to the transport of electrons into the p-doped cladding region. The cladding regions have a low Al mole fraction, so that they have a direct bandgap. This prevents carrier loss by trapping in the DX level in the cladding regions.