Abstract: A system for the transmission of signals along an optical carrier employs a technique to extend the effective frequency range of modulation beyond that of which a semiconductor laser is capable by combination of signals at the source to form a composite difference signal and recombination at the receiver to restore the original signal.

Abstract: An integrated optical pressure transducer having a diaphragm fabricated from a low-loss glass is positioned at the location where pressure changes are to be measured. An optical waveguide loop formed on one surface of the diaphragm acts as a ring cavity in which the difference between the resonating frequencies varies with pressure but not with temperature. Light energy is coupled into the waveguide loop from an optical source through a tangentially located input waveguide. An output waveguide, also tangentially located, couples light energy from the waveguide loop to a broadband detector so that the changes in frequency spectrum of the resonating frequencies within the waveguide loop can be monitored.

Abstract: A laser diode is soldered between metal plates for intimate thermal and electrical contact. The plates are prefabricated and are provided with an insulative spacer therebetween. The two metal plates are held together in a preferred orientation by the spacer which is firmly adhered and sealed to the two plates during the diode soldering operation. The metal plates are constructed from material thin enough that they yield under thermal pressure of the diode to eliminate mechanical strain on the diode during thermal cycling. Backup plates are provided in contact with the diode mounting plates to feed electrical energy thereto.

Abstract: High power operation in conjunction with excellent mode stability is rendered possible by a unique configuration comprising the use of two injection laser diode sections in a crossed-junction configuration.

Abstract: A laser diode is soldered between metal plates for intimate thermal and electrical contact. The plates are prefabricated and are provided with an insulated spacer therebetween. The two metal plates are held together in a preferred orientation by the spacer which is firmly adhered and sealed to the two plates during the diode soldering operation. The laser diodes so mounted can be tested in this configuration and after testing are formed into an array by stacking the laser diode subassemblies providing spacer elements therebetween and series contacts from one end to the other of the array so that an array of laser diodes with matched characteristics can be constructed in a line which may not be in alignment with the total package to provide an intense light output at a predetermined wavelength.

Abstract: A laser diode suitable for integrated and fiber optic applications requiring single transverse and single longitudinal mode operation. The single transverse mode is provided by making a gallium arsenide double heterostructural laser diode with a narrow stripe width and a relatively long length. The single longitudinal mode operation is provided by cracking the diode transverse to the stripe at one or more locations to form internal etalons in the laser cavity.

Abstract: A tapered crystal for use in a laser modulator in a communication system reduces switching voltage and driving power requirements. Alternately, the crystals are tapered for reduced crystal capacitance, thus decreasing the modulator rise time.

Abstract: An electrooptic crystal having improved characteristics including an improved light extinction ratio and a process of making same including etching certain portions of the lateral surfaces thereof so as to relieve surface and other strain in the crystal.