Abstract: Building-to-building over the air transmission of optical data is a growing area of data communications. The fast growing use of bandwidth mandates the use of over the air transmission equipment capable of similar performance as the performance of fiber optic transmission, for distances of 3-10 Km. Transparent transmission is important to enable seamless growth from low data-rare to Gbps rates, and then to Dense Wavelength Division Multiplexed (DWDM) transmission of several wavelengths. The only way to achieve the required performance is with narrow, directable beams. This patent application discloses a Micro-Electro-Mechanical-Systems (MEMS) mirror based, over the air, optical data transmission system. A narrow optical beam is used and a MEMS mirror fine-tunes the aiming of the beam to track building movement, vibrations etc.

Abstract: Building-to-building over the air transmission of optical data is a growing area of data communications. The fast growing use of bandwidth mandates the use of over the air transmission equipment capable of similar performance as the performance of fiber optic transmission, for distances of 3-10 Km. Transparent transmission is important, to enable seamless growth from low data-rate to Gbps rates, and then to Dense Wavelength Division Multiplexed (DWDM) transmission of several wavelengths. The only way to achieve the required performance is with narrow, directable beams. The present invention uses Micro-Electro-Mechanical-Systems (MEMS) mirror based, over the air optical data transmission system. A narrow optical beam is used and a MEMS mirror fine-tunes the aiming of the beam to track building movement, vibrations etc.

Abstract: An over-the-air optical data communications system includes a plurality of transmission units that are mounted at separate locations in a geographical area to establish a mesh network that includes a plurality of line-of-sight optical communications links. A network controller is electronically connected with each communications link to monitor transmission quality on the link, and to selectively aim each transmission unit in the mesh network to an alternate transmission unit as required to maintain the mesh network. Additionally, a backbone network holds the mesh network together by interconnecting various communications stations that are each connected with at least one transmission unit in each of the communications links.

Abstract: An array of nonuniform semiconductor diode lasers with supermode control for achieving a single-lobed farfield pattern is described. This is accomplished by spatially segregating the fundamental supermode from the other supermodes, tailoring the spatial gain profile as as to favor the fundamental supermode, and sufficiently increasing the intechannel coupling so as to bring about single-lobed farfield operation. In a preferred embodiment, this is achieved in a shallowly proton implanted, tailored gain, chirped laser array in which the widths of the lasers are varied linearly across the array.

Abstract: High transconductance vertical FETs are produced in III-V epitaxially grown layers doped n, p and n, with the in-between submicron (0.15 .mu.m) layer serving as the FET channel. The layer on the drain side of the channel may be thicker (3 .mu.m) than on the source side (1.5 .mu.m). The structure is V-grooved to expose a nearly vertical surface that is Si implanted or regrown with graded n-type GaAs/GaAlAs before a gate contact is deposited on the vertical structure. An alternative to employ a heterostructure with GaAlAs layers for the source and drain, and GaAs for the channel layer. Graded GaAs/GaAlAs is then selectively regrown in the channel layer.

Abstract: Alternating layers of N+ GaAs (80 .ANG.) and N+ Ga.sub.1-x Al.sub.x As (300 .ANG.), all heavily doped with a uniform flux of Sn, and biased by 2V, provide a multiple quantum-well heterojunction structure for infrared detection with cutoff wavelength established by the choice of the value x which defines the depth of the wells. Fine tuning of the cutoff wavelength may be achieved by varying the bias voltage. By biasing the individual quantum-well layers progressively through a voltage divider, an avalanche mechanism may be achieved in the detector for signal amplification. The detectors may be fabricated in large two-dimensional arrays.

Abstract: An integrated laser structure for paired stripe semiconductor lasers is provided with separate current control of each stripe laser. With optical coupling between the lasers, one of the lasers is operated below threshold and serves the longitudinal mode selection and tunability of the other laser, thereby to obtain a single longitudinal mode operation. Without coupling, the paired-laser structure operates as a source of two independent wavelengths.

Abstract: An arrangement for damping the resonance in a laser diode includes an additional layer (25) which together with the conventional laser diode form a structure (35) of a bipolar transistor. Therein, the additional layer serves as the collector, the cladding layer (12) next to it as the base, and the active region (11) and the other cladding layer (13) as the emitter. A capacitor (30) is connected across the base and the collector. It is chosen so that at any frequency above a certain selected frequency (f.sub.c) which is far below the resonance frequency (f.sub.res) the capacitor impedance is very low, effectively shorting the base to the collector.

Abstract: Solid state electro-optical devices are formed on a semi-insulating substrate, with all contacts of each device being on the same side of the substrate. These devices include two types of lasers, one operating on current crowding effect and the other by lateral diffusions. Either type laser is integratable with an electronic device e.g. a Gunn oscillator or an FET on the common semi-insulating substrate to form a complex monolithic electro-optical device.

Abstract: Solid state electro-optical devices are formed on a semi-insulating substrate, with all contacts of each device being on the same side of the substrate. These devices include two types of lasers, one operating on current crowding effect and the other by lateral diffusions. Either type laser is integratable with an electronic device e.g. a Gunn oscillator or an FET on the common semi-insulating substrate to form a complex monolithic electro-optical device.