Abstract: In a modulator integrated laser 100, a wave guide channel 200a in a modulator area 200 having a core constituted of an absorption layer 204 and a wave guide channel 250a at a laser area 250 having a core constituted of an active layer 254 are optically connected with each other by a wave guide channel 150a having a core constituted of a light wave guide layer 204b. The width of the light wave guide layer 204b increases in a continuous manner as the distance from the modulator area 200 increases and the width also increases in a continuous manner as the distance from the laser area 250 increases, with the width achieving its maximum in the vicinity of the middle area between the modulator area 200 and the laser area 250.

Abstract: A laser diode array comprises a plurality of substantially parallel spaced metal plates, each plate having a laser diode mounted upon one side of the plate. The plates are supported electrically insulated from one another on mounting means. The diodes, connected electrically in series, when energized illuminate an oblong workpiece area disposed a certain distance opposite the array. In a preferred embodiment, the mounting means comprises flexible rod means passing through respective apertures of the plates, thus enabling the array to assume a curved configuration, thereby enabling the array to illuminate a straight as well as a curved oblong workpiece area.

Abstract: A novel device and method of beam steering for semiconductor lasers or optical amplifiers is disclosed. The method of the present invention achieves high signal extinction ratios, high speed, low chirp modulation by biasing a multi-lateral mode beam steering section. The device of the present invention comprises an active single vertical and lateral mode optical waveguide, a multi-lateral mode waveguide, and a mode converter. The mode converter efficiently couples output from an active single mode waveguide to two or more modes of a multi-lateral mode waveguide. Two guided modes arrive at a device facet with a particular intermodal phase difference based on initial mode phasing, multi-lateral mode waveguide length and modal dispersion properties, and facet angle. Beam steering is achieved through carrier antiguiding effect by injecting current into the multi-lateral mode waveguide from the mode converter thus changing the intermodal dispersion.

Abstract: A semiconductor laser device structure comprising an active region provided by a quantum well of an indirect bandgap material, the quantum well being divided laterally to form an active region comprising a two dimensional array of localized cells. Preferably the quantum well of indirect band gap material is selected from group IV semiconductor materials and comprises a silicon-germanium alloy. A silicon/silicon-germanium alloy multi-quantum well (MQW) structure is described. In a preferred embodiment, a Si/SiGe alloy MQW laser diode comprises a coplanar double grating configuration etched through the MQW structure to provide distributed feedback. The double intersecting grating structure functions to define an array of "cells" or regions of finite dimensions in the quantum well structure which "localize" carriers within the cells thereby enhancing the radiative emission probability. The grating also provides for combined gain-coupled and index-coupled distributed feedback.

Abstract: A multiple wavelength quantum cascade (QC) superlattice (SL) light source has at least three energy levels in each radiative transition (RT) region, and electron transitions between the levels give rise to emission lines at different wavelengths. In one embodiment, a lower miniband has at least a first energy level and an upper miniband has at least third and fourth energy levels. In another embodiment, the lower miniband has first and second energy levels. In both cases, electron transitions between a first pair of the upper and lower levels generates light at a first spontaneous emission line having a center wavelength .lambda..sub.1 and a line broadening first energy, and electron transitions between a second pair of the upper and lower levels generates light at a second spontaneous emission line having a center wavelength .lambda..sub.2 and a line broadening second energy.

Abstract: A first, thicker, annular gallium arsenide semiconductor layer surrounds a second, thinner, circular gallium arsenide semiconductor layer in a vertical cavity surface emitting laser. The thinner circular gallium arsenide layer defines the output window for the laser cavity which matches the TEM.sub.00 fundamental mode of the light beam emitted by the active region of the VCSEL. The thicker annular gallium arsenide layer outside the output window of the thinner circular gallium arsenide layer provides modal reflectivity discrimination against high order transverse modes of the light beam emitted by the active region of the VCSEL.

Abstract: It is an object of the invention to effectively use semiconductor laser elements by suppressing difficulties caused by heat generated at the times of mounting and light emission in the semiconductor laser elements. A semiconductor laser module comprises a light source-mounting section, on which plural semiconductor laser elements are mounted and optical fiber-fixing section, which upports plural optical fibers at a predetermined lateral pitch. A pitch-converting section is provided between the light source-mounting section and the optical fiber-fixing section in order to respectively guide lights semitted from the semiconductor laser elements to the corresponding optical fibers. The light source-mounting section, the pitch-converting section and the optical fiber fixing section are formed on the same substrate.

Abstract: A tunable semiconductor laser comprises a gain section having an MQW active region, a uniform pitch grating DFB region, and first waveguide. A composite reflector, including a second MQW region and a second waveguide, forms a cavity resonator with the DFB region. A voltage applied to the composite reflector induces a quantum confined stark effect, thereby allowing the wavelength to be altered. In one embodiment, the current drive to the active region and the shape of the first waveguide (e.g., a raised-sine function) are mutually adapted so that N longitudinal modes have essentially the same threshold gain and so that the DFB region spanned by the first waveguide is segmented into N zones, each zone providing optical feedback at a different wavelength corresponding to a different longitudinal mode.