Abstract: An intracavity modulated pulsed laser and methods of using the same. In one preferred form, an intracavity modulated pulsed laser comprises an amplification medium, a pulsed pumping source, a beam modulator, and two mirrors, one totally reflective and one partially reflective for generating at least one laser output burst comprising a plurality of sub-pulses having variably controllable peak powers. In another preferred form, a non-linear crystal is utilized to double the frequency of each laser output burst. In still another preferred form, a fluorescence feedback control circuit is utilized to control the beam modulator.

Abstract: A semiconductor laser of this invention includes: a semiconductor substrate; a first cladding layer made of first conductivity type ZnMgSSe, which is held by the semiconductor substrate and lattice-matches with the semiconductor substrate; a stripe-shaped second cladding layer made of second conductivity type ZnMgSSe lattice-matching with the semiconductor substrate; a light-emitting layer including a first and a second light guiding layers made of Zn.sub.1-x Mg.sub.x S.sub.1-y Se.sub.y (0.ltoreq.x<1, 0.ltoreq.y<1) and a quantum well layer made of Zn.sub.1-z Cd.sub.z Se (0.ltoreq.z<1) which is interposed between the first and the second light guiding layers, the light-emitting layer being interposed between the first and the second cladding layers; and a burying layer which is made of ZnMgSSe lattice-matching with the semiconductor substrate and formed on sides of the second cladding layer.

Abstract: Grating-coupled surface emitting laser structures utilize strain-compensated multiple quantum wells as the laser gain medium, and are used in combination with a very high grating coupling efficiency to reduce both output beam spot size and overall device size. The lasers are designed with grating coupling coefficients that are much higher (e.g., greater than 150 cm.sup.-1) than those employed in conventional grating coupled lasers to achieve a substantial increase in the laser energy coupled vertically through the top surface of the laser. This permits a substantial reduction of the output laser beam size so that it can be easily matched to multimode, and even single mode optical fibers.

Abstract: Novel semiconductor devices are monolithically defined with p-type and n-type wide bandgap material formed by impurity induced layer disordering of selected regions of multiple semiconductor layers. The devices are beneficially fabricated by simultaneously forming the n-type and p-type layer disordered regions with sufficiently abrupt transitions from disordered to as-grown material. The novel devices include a heterojunction bipolar transistor monolithically integrated with an edge emitting heterostructure laser or a surface emitting laser, a heterostructure surface emitting laser, a heterostructure surface emitting laser having active distributed feedback, devices containing multiple buried layers which are individually contacted such as p-n junction surface emitting lasers, carrier channeling devices, and "n-i-p-i" or hetero "n-i-p-i" devices, and novel interdigitated structures, such as optical detectors and distributed feedback lasers.

Abstract: Photodiodes are integrally formed with vertical cavity surface emitting lasers (VCSELs) and superluminescent light emitting diodes (SLEDs) for monitoring optical radiation intensities. In different embodiments, the photodiode is epitaxially formed within a mirror of a VCSEL, non-epitaxially formed on top of a VCSEL, non-epitaxially formed on side of a VCSEL, or formed on the substrate on the side opposite the VCSEL. A lateral injection vertical cavity surface emitting laser is also disclosed for integration with a lateral PIN photodiode. A photodiode having the same epitaxial layers as a VCSEL is also integrally formed alongside of the VCSEL. Similar devices using SLEDs are also disclosed.

Abstract: A drive circuit drives an electronic device that converts electric power into light or heat energy. The drive circuit has a switch connected to the electronic device in series, and a control circuit for providing, in response to an input control signal, a pulse modulation signal for controlling the switch. The frequency of the pulse modulation signal is higher than the response frequency of the electronic device. Alternatively, the drive circuit may have first to fourth switches disposed on both sides of the electronic device, for passing a current in different directions through the electronic device, and a control circuit for controlling the switches to change the direction and magnitude of the average of the current flowing through the electronic device in response to an input control signal.

Abstract: A device suitable for a laser-type bar code reader used in a POS (point of sales) system in the distribution industry, and more particularly, to a laser lighting control device in a laser scanner device which reads a bar code using a reflection light of a laser beam. A prolonged operational life and an improved reliability of the laser light source build-in device under intermittent light on/off control is achieved by monitoring its lighting time to execute the operational life control thereof. The laser lighting control device includes a laser light source, a drive unit for performing a light on/off drive of the laser light source to control the light on/off thereof, a control unit for outputting a light on/off command to the drive unit for laser light source control, and a timer unit for measuring the total lighting time of the laser light source.

Abstract: A surface-emitting laser includes optically transparent layers on a side of a DBR mirror structure that is opposite to an optical cavity of the laser. In one embodiment, the transparent layer is a heat-conducting layer that has an efficient heat transfer relationship with an opening in a top electrode and with a heat-spreading layer. The heat-spreading layer increases the diameter of the electrode, so as to reduce the thermal impedance of the surface-emitting laser. The heat-spreading layer may be annular in shape and may have an inside diameter that is less than the outside diameter of the electrode, allowing the heat-spreading layer to first overlap the electrode and then overlap the portion of the heat-conducting layer that resides on the inside portion of the electrode. In another embodiment, the optically transparent layer is positioned between the top electrode and the top DBR mirror structure of the surface-emitting laser.

Abstract: A gain-guided type AlGaInP visible light laser diode in accordance with the present invention has a characteristic in that, an n-type current-blocking layer for the current constriction in the double-heterojunction structure in highly doped with n-type impurity so as to prevent the formation of p-type inversion layer therein. When an n-GaAs current-blocking layer is formed on a p-GaInP etching stopper layer doped with zinc, the n-type impurity concentration of the n-GaAs current blocking layer is selected to be 3.times.10.sup.18 cm.sup.-3 or more to achieve a large kink-light output at a low oscillation threshold current.

Abstract: A planar, topology free, semiconductor quantum-well laser is described. The quantum-well active layer is formed and patterned in a specified region which is constrained on all sides by high bandgaps which are formed through the use of impurity-free diffusion techniques. After the impurity-free diffusion has taken place, an upper portion is then epitaxially deposited to complete the structure. High-power, single fundamental mode laser operation is achieved by funneling current into the constrained quantum-well active region, high bandgap regions in conjunction with low index of refraction in regions surrounding the active area. The structure is further designed to allow low beam divergence in the direction perpendicular to the semiconductor laser junction.

Abstract: A diode laser source including a laser diode whose emitting element or elements is divided into a plurality of concurrently driven laser segments. Beam filling and focusing optics are disposed in front of the segments so that light from the segments in each element converges to a single overlapping spot. The optics include a beam filling lens array collimating the light from the segments and either a single focusing lens or a second lens array focusing the collimated light to corresponding spots. In the case of a multi-element laser diode array, each multi-segment element of the array is individually addressable so as to be driven independently from the other array elements. The segmentation of laser elements improves laser life by reducing thermal gradients and isolating any local failures to a single segment, while the focusing of the segments to overlapping light spots increases the tolerance of the source to local failures.

Abstract: A semiconductor laser includes a GaAs substrate, an active layer made of a semiconductor material having a band gap energy smaller than that of GaAs, and a top clad having an AlGaInP cladding layer. An index antiguiding type semiconductor laser is constituted based on the above structure. The top clad includes a base layer formed on the active layer and a protrusion strip for current injection protruding from the base layer and having an AlGaInP cladding layer. An AlGaInP light diffusion layer with an Al proportion smaller than that of the AlGaInP cladding layer and inclusive of zero is formed on the base layer adjacent to the protrusion strip. The base layer has a thickness so as to allow laser oscillation light to leak out to the light diffusion layer.

Abstract: A laser system wherein, in order that a high-output and high-quality single mode of a cross sectional area larger than the beam diameter determined by the construction of a resonator can be obtained stably, although this has heretofore been impossible, there is used a coupling mirror provided with a partial reflection film and an antireflecting film, a laser beam mode is selected using the partial reflection film, a phase difference between laser beam portions caused by a difference in construction between the partial reflection film and the antireflecting film is compensated using a phase difference compensating means, and there is formed an aperture whose diameter is set to a value of not larger than four times the diameter of the partial reflection film.

Abstract: A gallium nitride group compound semiconductor laser diode (10) satisfying the formula (Al.sub.x Ga.sub.1-x).sub.y In.sub.1-y N, inclusive of 0.ltoreq.x.ltoreq.1 and 0.ltoreq.y.ltoreq.1 comprises by a double hetero-junction structure sandwiching an active layer (5) between layers (4, 6) having wider band gaps than the active layer (5). The active layer (5) may comprise magnesium (Mg) doped p-type conductive gallium nitride group compound semiconductor satisfying the formula (Al.sub.x Ga.sub.1-x).sub.y In.sub.1-y N, inclusive of 0.ltoreq.x.ltoreq.1 and 0.ltoreq.y.ltoreq.1 . In another embodiment, the active layer (5) is doped with silicon (Si).

Abstract: A quantum-well semiconductor laser/amplifier mounted on a highly conductive semiconductor substrate. Inactive regions include a highly doped N-region and a highly doped P-region. The N-region is composed of semiconductor material mounted on the substrate. The active region includes a quantum-well heterostructure of intrinsic semiconductor material that mounts on the N-region. The quantum-well structure includes a series of quantum wells, each having barrier layers, quantum-well layers, and a delta-strained layer mounted near the center of the quantum wells. The delta-strained layers are very thin, being formed from a number of mono-layers of semiconductor material. There is a large lattice mismatch between each of the delta-strained layers and its adjacent quantum-well layers. The band edges of the quantum-well layers and the delta-strained layers are located at substantially the same level. The P-region is composed of a semiconductor material that mounts on the quantum-well structure.

Abstract: A semiconductor laser including a compound semiconductor substrate of an n-type, a semiconductor laser chip region defined at a center portion of an upper portion of the compound semiconductor substrate and provided at its front and rear surfaces with mirror surfaces for oscillating laser beams, and a pair of guide regions defined at opposite sides of the chip region, respectively, to be in contact with the semiconductor laser chip region. The chip region has a shape of a hexahedron. Together with the front and rear surfaces of the chip region, the guide regions define a cavity for coupling the chip region with external elements at the compound semiconductor substrate. The semiconductor laser also includes a first electrode formed over the chip region and guide regions and adapted to receive an electric power for generating laser beams and a second electrode formed beneath the semiconductor substrate and adapted to receive the electric power for generating laser beams, together with the first electrode.

Abstract: A tunable [tunable] surface-emitting laser diode in which in the manner of the TTG laser diode an active layer (5) and a tuning layer (3) are arranged transverse to one another between contact layers (2, 6) and are separated from one another by a central layer (4), with the result that given suitable doping of the surrounding semiconductor material these layers can be driven separately, and in which above a region provided for generating radiation the semiconductor material has on the surface a spatial periodic structure which is provided with a thin metallic film (7), with the result that during operation of the laser diode radiation is emitted directionally from the surface by means of exciting surface plasmon polaritons, and that this emission direction can be varied by tuning the wavelength of the radiation.

Abstract: An edge emitting laser device with at least two laser structures arranged in one and the same optical cavity. The laser structures are substantially arranged in the optical direction of propagation and each laser structure comprises an active region, said active regions being electrically connected in series.

Abstract: The semiconductor laser of the present invention has an active layer in which the output edge is formed into a V-shape or comprises a striped active layer which is present in a pumped region and whose light output edge is transversely bent.

Abstract: The disclosure describes a method of forming a groove in a structure of a semiconductor laser diode, which comprises a crystal growth procedure of epitaxial growth of a core layer comprising MP, wherein M represents one or more of elements belonging to group IIIb of periodic table and an upper layer comprising MAs, wherein M represents one or more of elements belonging to group IIIb of periodic table, successively on (100) surface of MAs crystals in a lower layer comprising MAs; a photolithography and wet etching procedure of, after forming an etching mask on the upper layer, forming an etching window to the etching mask; a first etching procedure of selective etching the upper layer; and a second etching procedure of selective etching other faces except for the face in which (111) face of MP crystals in the core layer is exposed.