Abstract: In a self-pulsing multi-section laser having two DFB sections, a Fabry-Perot-like resonator formed from two reflectors and a spacer is integrated into the multi-section laser and optically coupled to at least one DFB section. The spacer has a similar layer structure to the adjacent DFB sections (D.sub.1 and D.sub.2) but not DFB grid and takes the form of a control section operable electrically separated from the DFB sections. Selection is unnecessary. The self-pulsing two-section DFB laser of the invention with an integrated control section is suitable for optical beat regeneration in high-rate communication systems.

Abstract: Use of the method allows MRCW high-temperature laser diodes with a coupled optical waveguide to be produced in four epitaxial steps. The advantage is that, of the four epitaxial processes the first two and the last two are carried out virtually immediately successively after one another and an interruption is necessary only to produce a grating. Other components, such as photodiodes for example, can also be produced using the method.

Abstract: VCSEL for high speed operation and method of fabrication including a substrate element, a first stack of distributed Bragg reflectors disposed on a surface of the substrate element, an active region lattice matched to a surface of the first stack of distributed Bragg reflectors, and a second stack of distributed Bragg reflectors lattice matched to a surface of the active region. The active region includes a plurality of quantum well layers, or structures, and a plurality of doped barrier layers. The doping of the barrier layers allows for a faster recombination time of the carriers prior to any occurrence of lateral carrier diffusion. This faster recombination time of the carriers prevents turn-off tails when the VCSEL device is switched off.

Abstract: A semiconductor laser is disclosed, which realizes a continuous oscillation in a fundamental transverse mode at a low operating voltage by a transverse mode control. This semiconductor laser is fabricated by forming successively the following layers on a sapphire substrate 10 in the order an n-type GaN contact layer, an n-type GaAlN cladding layer 13, an MQW active layer 16, a p-type GaAlN cladding layer 19, wherein the laser comprises a double heterostructure including a ridge in the shape of a stripe formed in the cladding layer 19 and a light confining layer 20 formed in a region except the ridge portion of the cladding layer 19 on the double heterostructure, wherein a refractive index of the light confining layer 20 is larger than that of a p-type GaAlN cladding layer.

Abstract: The lateral confinement region provided on both sides of an active region stripe of a buried heterostructure laser is formed of an alloy of InGaAsP instead of the conventional Fe doped InP material. This results in much improved regrowth morphology while still achieving good current and light blocking properties.

Abstract: The present invention relates to high power semiconductor laser device and method for fabricating the same utilizing ion implanting process, by which a beam steering phenomenon of an optical output due to filaments is eliminated. This elimination is achieved by a periodically varying gain given for a resonator of the semiconductor laser device. That is, this invention changes a gain distribution which causes the generation of filaments in the resonator into different distribution. According to the present invention, there is formed an insulation layer through ion implantation to an active layer to adjust current density implanted to the active layer, thereby eliminating non-uniform distribution of the light along the longitudinal direction of the resonator.

Abstract: An extended VCSEL structure formed of a first DBR mirror, an active region, a second DBR mirror as partial reflector, and an extended cavity provided by a transparent conductive substrate wafer fused onto the second DBR mirror. The transparent conductive substrate also serves as a convex mirror with a highly reflective dielectric coating to complete the extended cavity VCSEL structure. The use of the extended cavity makes high power single mode operation achievable because an extended cavity introduces high modal loss to the high order laser modes while supporting the lowest order single mode. The large active area allows high output power from the VCSEL.

Abstract: A semiconductor Bragg reflector and to a method of fabricating it. The reflector comprises a plurality of stacked layers on a substrate of a III-V type material, one of the stacked layers forming a holographic grating. The layer forming the grating comprises an alternating succession of air pockets and of III-V type material. Such a reflector is particularly suitable for use in laser devices.

Abstract: A parallel optical data link using multimode optical components. The invention includes an array of photonic optical sources and an array of multimode waveguides optically coupled adjacent to the array of sources. Similarly, the invention further includes an array of photonic optical detectors and an array of multimode waveguides optically coupled adjacent to the array of detectors. The invention further includes a multimode optical fiber ribbon having a longitudinal dimension and first and second opposing extremities for transmission of light there through. The source coupled waveguide array is in optical communication with the first extremity of the fiber ribbon, while the detector coupled waveguide array is in optical communication with the second extremity of the fiber ribbon.

Abstract: In a surface-emitting laser comprising an active region which includes a light emitting layer and two mirrors which sandwich the active region, at least one of the two mirrors has a distributed Bragg reflector structure which comprises a plurality of first layers including aluminum and a plurality of second layers different from the first layers. At least one selected layer of the first layers has a selective oxide region including aluminum and a core semiconductor region surrounded by the selective oxide region.

Abstract: A semiconductor laser is provided having excellent characteristics such as long life, less variable threshold current due to the temperature change, and low noise, by effectively preventing leakage of electrons from the active layer. The semiconductor laser is provided with a electron barrier layer and the guide layer of the laser is doped with an n-type dopant, such that a high electron barrier is constructed between the guide layer and the cladding layer.

Abstract: A method for doping semiconductors used for far infrared lasers with non-hydrogenic acceptors having binding energies larger than the energy of the laser photons. Doping of germanium or silicon crystals with beryllium, zinc or copper. A far infrared laser comprising germanium crystals doped with double or triple acceptor dopants permitting the doped laser to be tuned continuously from 1 to 4 terahertz and to operate in continuous mode. A method for operating semiconductor hole population inversion lasers with a closed cycle refrigerator.

Abstract: A wavelength division multiplexer is provided that integrates an axial gradient refractive index element with a diffraction grating to provide efficient coupling from a plurality of input optical sources (each delivering a single wavelength to the device) which are multiplexed to a single polychromatic beam for output to a single output optical receiver.

Abstract: The present invention relates to a vertical cavity surface emitting laser device comprising a plurality of semiconductor layers formed upon a substrate and capable of emitting a laser beam of a selected wavelength and a selected polarization, wherein said polarization is established by the presence of stress inducing elements disposed on said free surface of the laser device which induce a stress in the active layers of the laser device. The stress inducing elements are made of a material having a higher coefficient of thermal expansion than the material which comprises the surface layer of the laser device.

Abstract: The invention relates to a method of preparing an improved cable and an improved optical fiber cable comprising a central reinforcement member and a plurality of loose tubes as laying elements, placed longitudinally around the central reinforcement member. The loose tubes comprising at least one or more optical fiber filaments. A gel filling material is contained in both the inner section as well as the outer section of the loose tubes. A layer encircling the assembly is selected from the group consisting of an aramide fiber layer, a fiber glass and combination thereof. At least one or more plastic cover is placed longitudinally over the fiber layer to support metal ribbons which are peripherally incorporated to the assembly and a second layer of plastic cover is placed over the metal ribbon.

Abstract: A monolithic long-wavelength vertical optical cavity device built up along a vertical direction. The device, when designed as a surface emitting laser, has a bottom Distributed Bragg Reflector (DBR), an active region consisting of active bulk medium or quantum wells, a current confinement layer next to the active layer, and a top DBR. The bottom DBR and the active region are lattice matched to the lattice defining material, while the top DBR is lattice relaxed. The design achieves high reflectivity, low absorption and diffraction loss. The design also ensures low production cost due to low precision requirement and wafer size production. The device can be used as a light detector when the active region is replaced by a spacer or a optical filter.

Abstract: An array of laser diodes, or laser diode bars, is formed by positioning adjacent diodes or bars in an offset or staircase arrangement where the emitting facets of adjacent diodes, or bars, are in different planes. The offset arrangement permits the light from adjacent facets to be separated a distance q much shorter than permitted by prior art stacking arrangements because thermal and mechanical constraints characteristic of prior art stacks, are relaxed considerably in the offset arrangement. Power densities of 2000 watts/cm.sup.2 (cw) are achieved with spacings of 0.6 mm between adjacent laser bars, a ten fold increase in power density over in-plane (prior art) positioning of like components.

Abstract: A gallium nitride-based compound semiconductor laser has a double-heterojunction structure, in which an active layer is sandwiched between cladding layers, on a sapphire substrate. A GaN current blocking layer having a striped opening portion is formed on the p-cladding layer. A p-GaN buried layer and a contact layer through which a current is injected into the opening portion of the current blocking layer and which are larger in area than the opening portion are formed. The active layer has a multiple quantum well structure constituted by a cyclic structure formed by cyclically stacking two types of InGaAlN layers which have different band gaps and are 10 nm or more thick.

Abstract: In a semiconductor laser for analog modulation, intermodulation distortion at high temperatures and/or at high outputs is reduced. In a DC-PBH semiconductor laser, the width (Wm) of the electrode mesa 11 is set at 10 .mu.m or less, and the width of each recombination layer 2 is set at 0.1 .mu.m or more. Further, the distance between one end of the active layer 1 and one end of each current-blocking layer 5 is set at 0.01 .mu.m to 0.5 .mu.m.

Abstract: A laser beam emission apparatus that may be used as a universal optical pickup laser light source. The apparatus may be used in various applications including recording/reproduction of data to/from various types of optical disks in various recording/reproducing modes. The apparatus includes a first semiconductor laser chip that emits a first laser beam at a first wavelength, and a second semiconductor laser chip that emits a second laser beam at a second wavelength different from the first wavelength. The emitted second laser beam has a plane of polarization that is perpendicular to the plane of polarization of the emitted first laser beam. The apparatus further includes a polarized beam splitter that transmits one of the laser beams and reflects the other laser beam, and a semiconductor substrate that has the laser chips and the polarized beam splitter mounted thereon.