Abstract: A surface emitting light emitting device with a semiconducting substrate, a semiconducting mirror stack positioned on the substrate surface, a spacer layer positioned on the mirror stack, an active region positioned on the spacer layer, a second spacer layer positioned on the active region, a second semiconducting mirror stack positioned on the second spacer layer, and a top contact layer positioned in contact with the second semiconducting mirror stack. The active region includes multiple quantum wells each having a different transition wavelength and positioned on the spacer layer with the quantum well possessing the longest transition wavelength located closest to the spacer layer and additional quantum wells of the multiple quantum wells positioned in order of decreasing transition wavelength so that the sum of the emission from all of the quantum wells results in a broad and uniform output emission spectrum.

Abstract: A surface emitting laser diode comprises a circular grating defined on the top surface of the diode for emitting a laser therethrough, an active layer for generating the laser in the region thereof under the circular grating, a reflection layer for preventing the laser from emitting through the bottom surface of the diode and a first contact, which includes a plurality of electrodes, for providing the active layer with carriers of a first conduction type and a second contact for providing the active layer with carriers of a second conduction type.

Abstract: The present invention is directed to a semiconductor laser device in which an active layer is constituted by a quantum well layer having a structure in which well layers and barrier layers which are formed on a GaAs substrate are alternately layered, cladding layers are provided so as to interpose the active layer, the value of a strain on each of the well layers is -0.8% to -1.5%, the thickness of a well layer is from 80 .ANG. to 180 .ANG., the value of strain on each of the barrier layers is +0.5% to +1.0%, the thickness of the barrier layer is 20 .ANG. to 60 .ANG., and the respective numbers of layered well layers and barrier layers are 2 to 4.

Abstract: A semiconductor laser oscillator structure and method is described having a tapered gain region in one-half of a laser cavity and a confocal oscillator region in another half of the cavity. An aperture is formed between two pairs of cavity spoilers located between the two cavity halves. One pair of spoilers is provided for receiving light which is reflected off of an output facet back into the semiconductor and removing it from the gain region. The other pair of spoilers removes light reflected from a curved mirror surface formed at the end of the other laser cavity half.

Abstract: A solid-state laser architecture producing a beam of extremely high quality and brightness, including a master oscillator operating in conjunction with a zig-zag amplifier, an image relaying telescope and a phase conjugation cell. One embodiment of the laser architecture compensates for birefringence that is thermally induced in the amplifier, but injects linearly polarized light into the phase conjugation cell. Another embodiment injects circularly polarized light into the phase conjugation cell and includes optical components that eliminate birefringence effects arising in a first pass through the amplifier. Optional features permit the use of a frequency doubler assembly to provide output at twice optical frequencies, and an electro-optical switch or Faraday rotator to effect polarization angle rotation if the amplifier material can only be operated at one polarization.

Abstract: A semiconductor multiquantum well structure is provided, which includes semiconductor well layers for forming quantum wells and semiconductor barrier layers for forming potential barriers each of which is arranged between adjacent two of the well layers. Each barrier layer is 7 nm or less in thickness. A number of the well layers is selected dependent upon the thickness of each barrier layer so that carriers or electrons and holes are injected into the respective quantum wells substantially uniformly. The number of the well layers is preferably 5 or more, and in the case, each barrier layer preferably ranges from 5 nm to 7 nm in thickness. A semiconductor laser having superior distortion characteristics at a high-frequency band such as 1 GHz can be provided.

Abstract: A laser diode has its frequency locked to the frequency of an absorption line of rubidium (water and oxides of nitrogen are also disclosed). The level of absorption, and hence the frequency relationship of the laser light with respect to the absorption line is detected by a photodetector. The absolute frequency of the laser light is guaranteed by initially adjusting the temperature of the diode until the frequency of the light is brought into coincidence with a first absorption line, subsequently maintaining the temperature at a constant level, and adjusting the drive current of the diode until the frequency of laser light achieves coincidence with an adjacent transition line. This ensures that the diode frequency is locked to the same absorption line each occasion the diode is switched on. Additionally, the change in drive current between coincidence with the two adjacent absorption lines is monitored as a further check that the correct transition line has been selected.

Abstract: A semiconductor laser includes a semiconductor laser chip stack having active layers formed substantially in the central portion thereof in the stacking direction and a pair of opposed reflecting surfaces formed at both ends of the active layers. A convex lens of a light transmissible material fixedly attached to a partially light transmissible reflecting surface of the pair of reflecting surfaces and adapted for converging a laser beam emitted from the partially light transmissible reflecting surface.

Abstract: In an optical modulator including a laser light source emitting laser light and a modulator, a modulation signal source for applying a modulation signal to the modulator, a signal processor for producing and outputting a signal in response to a change in the modulation signal, and a driving current source for generating a driving current applied to the laser light. Wavelength chirping modulation reverse to the wavelength chirping occurring in the modulator is produced in the light emitted from the laser by modulation of the driving current whereby wavelength chirping produced by the modulator is at least partially cancelled and wavelength chirping of the light output from the modulator is reduced.

Abstract: The disclosed integrated modulator/laser (I-MOD/DFB) combination comprises an active region that extends the full length of the combination without variation of layer thickness and/or composition. Because of this constancy of the active region parameters the relevant bandgap energy is the same in the laser portion of the combination as in the modulator portion thereof. The combination typically comprises a distributed feedback structure (e.g., a "grating"). In preferred embodiments the feedback structure is selected such that .lambda..sub.e >.lambda..sub.o (typically .lambda..sub.e -.lambda..sub.o in the range 20-70 nm), where .lambda..sub.e is the laser output wavelength, and .lambda..sub.o is the wavelength of the gain peak of the laser medium. The active region can be a bulk active region but preferably is a quantum well active region. Optionally an I-MOD/DFB combination according to the invention can comprise an absorbing region, e.g.

Abstract: A corner reflector (2) is applied for a laser head to couple collimated pump beams (3) emitted from one or more diode bars (5, 8) transversely into the laser rod (1) with an even 4-sided pumping. A Keplerian telescope (23) with internal nonlinear crystal (27, 37) is employed for a compact cavity design, to achieve mode-matched pumping, compensation of the thermal lens effect, and efficient intracavity frequency conversion.

Abstract: There is provided a semiconductor laser device comprising a lower optical confinement layer 31, an active layer 3 and an upper optical confinement layer 34, said active layer 3 being inserted between said upper and lower optical confinement layers 31 and 34, characterized in that an electron injection path (along an n-type electrode 10.fwdarw.the upper optical confinement layer 34.fwdarw.the active layer 3) for injecting electrons into the active layer 3 by way of the optical confinement layers and a hole injection path (along p-type electrodes 6.fwdarw.the p-type InP layer 5.fwdarw.the active layer 3) for injecting holes into the active layer 3 without passing through the optical confinement layers are formed therein. With such an arrangement, electrons are injected into the active layer by way of the optical confinement layers, whereas holes are injected into the active layer without passing through the optical confinement layers.

Abstract: A semiconductor laser that includes a monolithic submount with a light emitting source aligned along one side thereby defining a radiation path over which the emitted light propagates. The submount includes two notches that flank the light emitting source. A micro-lens is mounted adjacent to the light emitting source by attaching to the submount with either epoxy or solder. Finally, the components of the semiconductor laser have matching coefficients of thermal expansion so that the optical alignment of the light emitting source and the micro-lens is maintained notwithstanding thermal cycling.

Abstract: A vertical emission laser structure comprising an active region between stacks of layers forming Bragg reflection mirrors respectively of the n-type and of the p-type, wherein: the stacks of layers are formed by different pairs of materials in the n-type mirror and in the p-type mirror; the pair of materials constituting the n-type mirror comprises materials having a conduction band gap that is narrow or even non-existent; and the pair of materials constituting the p-type mirror comprises materials having a valance band gap that is narrow, or even non-existent.

Abstract: A semiconductor laser including a semiconductor substrate of a first conductivity type; a semiconductor multilayer structure disposed on the substrate and including a first cladding layer of the first conductivity type, an active layer, a second cladding layer of a second conductivity type, opposite the first conductivity type, and a current blocking layer of the first conductivity type; a laser light emitting facet; a stripe-shaped V groove extending in a resonator length direction transverse to the laser light emitting facet and penetrating in a depth direction into a part of the semiconductor multilayer structure, including into the second cladding layer, the stripe-shaped V groove having a width transverse to the resonator length direction and the depth direction wherein at least one of the depth and width of the stripe-shaped V groove has a first dimension adjacent the laser light emitting facet and a second dimension, different from the first dimension, within the semiconductor laser spaced from the las

Abstract: An integrated semiconductor laser and light modulator includes a semiconductor laser disposed at a first region on a semiconductor substrate, a light modulator of an electric field absorbing type disposed at a second region on the semiconductor substrate adjacent to the first region for outputting a modulated light by transmitting or absorbing the laser light generated in the semiconductor laser, a semiconductor laminated layer structure including a quantum well structure layer disposed in the first region and the second region on the semiconductor substrate, and a lattice mismatched layer having a lattice constant smaller than that of the semiconductor substrate, disposed on a part of the semiconductor laminated layer structure, in the second region. It is possible to enhance the transmission efficiency of the laser light to the light modulator and the quality of the active layer of the semiconductor laser and the light absorption layer of the light modulator.

Abstract: A semiconductor light emitter, such as the light-emitting diode or the semiconductor laser, having a structure in which a light emitting area or an active layer; a transparent layer which is pervious to light radiated from the light emitting area or the active layer; and an opaque layer or an opaque substrate which is impervious to the radiated light are arranged in order or in the inverse order. The semiconductor light emitter includes (a) total reflection layer(s) arranged between the transparent layer(s) and the opaque layer(s) so as to come into contact with the transparent layer. The refractive index of the total reflection layer is smaller than that of the transparent layer. Therefore, at least one part of light, which has been radiated from the light emitting area or the active layer and which has been reflected by the total reflection layer thereafter, is either radiated outward from side surfaces of the transparent layer or returned to the active layer.

Abstract: There is disclosed an illuminating light source device suitable for illumination at a vibrating place or a portion where an electric lamp is hardly exchangeable for new one, as well as for general luminairs. The illuminating light source device comprises a semiconductor laser element for outputting a laser beam of a particular wavelength in the range from infrared rays to ultraviolet rays, a lens for diffusing the laser beam from the semiconductor laser element and a fluophor for converting the diffused laser beam from the diffusion lens into visible light. Otherwise, the illuminating light source device comprises a group of semiconductor laser elements for respectively outputting laser beams of three primary colors consisting of red, green and blue, a lens for diffusing the laser beam from each of the semiconductor laser elements, and lenses for superposing the diffused laser beams from the diffusion lenses.

Abstract: A semiconductor laser device which allows high speed correction of the position of a laser spot on an optical disk is disclosed. The semiconductor laser device comprises an active layer which oscillates a laser beam when electric current is supplied thereto, and a plurality of independent electrodes for varying the current density distribution in the active layer to vary the intensity distribution of the laser beam to be emitted from an emergent face of the semiconductor laser device. With the semiconductor laser device, by supplying electric currents individually from the plurality of independent electrodes to vary the current density distribution in the active layer, the beam spot position can be corrected within the frequency bandwidth of several tens MHz by direct modulation of the semiconductor laser device. Also a driving method for the semiconductor laser device and a tracking servo system in which the semiconductor laser device is incorporated are disclosed.

Abstract: A semiconductor double heterostructure formed on a GaAs substrate having an off (100) plane slightly tilted toward a predetermined direction, the double heterostructure including an InGaAs quantum well active strained layer sandwiched between potential barrier layers and including an interface between the InGaAs quantum well active strained layer and an upper potential barrier layer grown on the active strained layer, wherein the interface has a periodical ridge-like bunching structure comprising quadrilateral waveform parts and triangular waveform parts, each of the quadrilateral waveform parts comprises a series of a bottom terrace of the just (100) plane, a reverse direction multiple step plane largely tilted from (100) direction toward the opposite direction to the predetermined direction, a top terrace of the just (100) plane and a forward direction multiple step plane largely tilted from (100) direction toward the predetermined direction, each of the triangular waveform parts comprises the just (100) pl