Abstract: A device for shifting the phase of light propagating through an optical fr, comprising a microbend transducer to bend the optical fiber. The microbend transducer comprises first and second transducer blocks each having a set of teeth positioned so that they face each other with a passageway therebetween through which the optical fiber passes and is bent by them. A device for modulating the intensity of light propagating through an optical fiber which has two tapered ends, comprising first and second mode strippers each operably attached to one of the tapered ends of the optical fiber and a microbend transducer disposed to bend the optical fiber.

Abstract: An apparatus for amplifying a laser beam through injection locking of a laser array by a single master laser is presented. The apparatus is comprised of a master laser which produces a beam that is shaped or focused onto a laser array facet which is further comprised of an array junction plane wherein the laser array is biased above threshold.

Abstract: An acousto-optic frequency shifter in which two cylindrical acoustic resonators driven 90.degree. out of phase from one another are placed around a birefringent, single-mode optical fiber approximately three-quarters of a polarization beat length apart. The resonators interact with optical radiation propagating in one of two polarization modes of the fiber, the first to cross-couple two sidebands into the other polarization mode, and the second to suppress one of the sidebands in the cross-coupled mode and enhance the other, thereby creating a single sideband signal completely within the fiber.

Abstract: An optical frequency division multiplex system including a transmitter, a receiver, and a transmission path connecting the transmitter to the receiver. In the transmitter a master laser is operated to produce a central peak at an optical frequency f.sub.o with side peaks separated by an amount .DELTA.f running to both sides of the central peak. The master laser output goes through an optical isolator to an optical coupler where it is split up into N+1 beams. Each optical output from the coupler is then positioned to be coupled into N slave lasers. Each slave laser is tuned to approximately coincide with one of the side peaks thus producing a single output frequency of (f.sub.o .+-.n.DELTA.f) from each slave laser diode. Electrical modulating signals for each of N information channels are applied separately to modulate the phase of each of the slave laser outputs. The outputs of the slave lasers are then recombined in a N.times.

Abstract: A device and method for interconnecting multiterminal electronic devices. e device and method combine the use of input light sources, output light detectors and an optical waveguide matrix device for routing the signals from various preselected input terminals to various other output terminals. The optical waveguide matrix device includes a number of intersecting optical waveguides formed on a base. The intersecting waveguides are optically coupled by means of reflecting surfaces formed at the nodes of intersection.

Abstract: A fiber optic interferometric physical sensor. A fiber optical Mach-Zehnder interferometer includes a sensor arm and a reference arm having different optical path lengths. A transducer coupled to the sensor arm modulates the phase of light signals passing therethrough in response to a physical quantity. The interferometer is supplied with an input optical signal which includes light components at two different wavelengths. The detected intensity of the output of the interferometer includes two components, each of which vary in relation to the physical quantity. Each output component is related to one of the two optical input wavelengths. The two output components differ in phase by an amount proportional to the path length difference between the sensor and reference arms and proportional to the wavelength difference between the light components of the input optical signal.

Abstract: An optical fiber magnetometer utilizing, in one embodiment, a birefringment optical fiber in combination with a magnetostrictive block for inducing strains in the fiber in response to an applied magnetic field to thereby cause a change in the degree of birefringence of the fiber. This change in birefringence is measured by directing the light exiting the fiber through a conversion element such as a polarizer or a prism and then detecting the resulting intensity modulation in a photodetector.A variety of inventive features are set out in this disclosure including the use of spliced fibers with a 90 degree axis rotation to compensate for environmental effects, the use of a twisted fiber for gradient field sensing, and the rotation of the sensor fiber to eliminate low-frequency noise and to obtain a vector field and field gradient sensing capability.

Abstract: The optical injection-locking of an FET oscillator is accomplished by injecting the beat signal between two coherently mixed slave lasers, which are locked to different harmonics of a modulated master laser, into the FET oscillator to be locked. 120 GHz injection-locking beat signals are possible using this technique.

Abstract: Transferred-electron device (TED) microwave burst and single pulse generators which are triggered by picosecond optical pulses. The burst generator includes a TED having a cathode, an anode, and a gate electrode positioned therebetween, all located on a semiconductor substrate. An optical pulse applied to the substrate between the gate and anode electrodes causes a plurality of space charge domains to sequentially travel from the gate to the illuminated region thereby causing an oscillatory burst of current to occur in the external leads of the TED. The frequency of the burst is proportional to the distance between the gate and the illuminated region and the burst duration is proportional to the optical pulse amplitude and/or duration. Alternatively, the burst generators may be formed from a two terminal TED with the cathode electrode being treated as the gate. A single pulse generator may be formed by applying an optical pulse to the substrate between the cathode and the gate of a three terminal TED.

Abstract: An optical fiber coil rotation rate sensor including provision for equal intensity dual inputs to its fiber coil to allow the device to operate at the quadrature point and circuitry to continuously adjust the phase in order to maintain operation at that quadrature point regardless of the rotation rate. The system includes an optical fiber coil for counterpropagating light beams therethrough and an input circuit for providing a first and second equal intensity light beams for counterpropagation through the fiber coil. The input circuit comprises a laser light source, a beamsplitter for splitting light from the laser source into two equal intensity beams, first and second elongate fiber waveguides for directing the equal intensity beams to the fiber coil for counterpropagation and including two elongate coextensive close-proximity sections for light beam coupling between the fiber waveguides, and a phase shifter circuit for automatically nulling the phase-shift in the beams returning from the coil.

Abstract: An optical technique for detecting acoustic waves of selected frequency and determining their angle of arrival in a medium such as water. The technique utilizes one or more lengths of single mode optical fiber having a birefringence whose orthogonal axes are helically disposed throughout the length of the fiber at a predetermined uniform pitch. Sound pressure waves of certain frequencies incident upon the fiber throughout its length change its birefringence which affects the relative phase of polarized light components propagating from one end to the other by an amount proportional to the amplitude of the acoustic wave. The twisted optical fiber may be arranged in parallel with other like fibers and axes twisted at different pitches thereby enabling detection of sound waves over a range of frequencies and their angles of incidence.

Abstract: An electro-optical modulator/antenna operates in the tunable diffraction ting mode to vary the magnitude of the zero diffraction order and consequently transmits optical information. A relatively thin slab of lithium niobate or equivalent electro-optic material has its lateral surfaces optically polished and its C-axis, or optical axis, running parallel to the polished lateral surfaces. At least one set of interdigital metallic electrodes are deposited on the face or just within the lateral surfaces to form, among other things, a diffraction grating that is orthogonally disposed with respect to the C-axis. When a potential source is coupled to the interdigital electrodes, the electric fields between adjacent electrodes change the crystal's index of refraction in accordance with the linear transverse Pockel's effect.

Abstract: A device for detecting optical energy signals in an optical path is provi by combining a layer of photoemissive material overlying the optical path and a grounded first electrode positioned in electrical contact with the layer of photoemissive material; a second electrode is positioned in spaced, preferably parallel relationship from the first grounded electrode and a source of dc potential is connected across the electrodes. Upon the transmission of optical energy signals along the optical path, commensurate electrical signals are produced across a load resistance which is connected between the second electrode and the high potential side of the dc potential source. Alternatively the concept may be embodied in a photomultiplier responsive to signals in an optical path. In this embodiment a plurality of dynodes are positioned between the first and second electrodes, spaced at gradually increased distances from the layer of photoemissive material.

Abstract: A fiber optic delay line filter receives light energy input signals repretative of any form of temporally varying signals such as electrical or acoustical, for example. A plurality of fiber optic light paths each having a determinably variant optical propagation delay, receives and transmits the light energy signals. A photo responsive means receives the delayed output light energy signals transmitted by the plurality of fiber optic light paths and produces a single electrical output signal as a function of the sum of the delayed output light energy signals, thus performing a filtering or correlation function. In a preferred embodiment, an injection laser or light emitting diode may be employed as the means for converting the temporally varying input signals to commensurate light energy signals.

Abstract: A plurality of identical dielectric channel optical wave guides is fabricd in a single crystal substrate of linear electro-optic material and a source of linearly polarized light is arranged to transmit its light energy along each of the optical waveguides. Electrodes are disposed contiguous to the optical waveguides for impressing electric fields thereacross. An input signal potential is applied to the electrodes to produce electric fields of intensity relative to each of the waveguides such that causes phase shift and resultant change of polarization which can be detected as representative of a binary "one" or binary "zero" for each of the channel optical waveguides. The resultant binary output is the multiple bit analog-to-digital conversion of the analog potential having amplitude V impressed upon the converter.

Abstract: A common substrate supports a plurality of waveguides numbering one more n the number of bits in the binary addends to be summed. Linearly polarized light is transmitted along each of the waveguides and a plurality of electrodes connectable to an electrical potential representative of a binary bit. The electrodes have discrete lengths contiguous to the waveguides for causing .pi.-radian phase retardation of light propagation upon application of the electrical potential. A polarization separator receives the output of each waveguide and produces signals commensurate with orthogonally polarized components. Photo detectors responsive to the signals representing each of the components produce commensurate electrical output signals which are, in turn, amplified and compared in an analog comparator for producing a binary output signal representative of the relative amplitudes of each pair of signals representing the orthogonally polarized components in each of the waveguides.

Abstract: Two light paths are disposed to induce resonant coupling of light energy from one path to the other. Electrodes connected to an electrical source are positioned relative to the two light paths and to develop electric fields which inhibit the resonant coupling from one light path to the other. A photoconductive region is positioned in one of the two light paths or in an additional third light path so that transmission of light energy through the photoconductive material produces a lowered resistance path between the electrodes, substantially diminishing the potential across the electrodes, and causing commensurate dimunition of the electric fields so that resonant coupling is inhibited between the resonantly coupled optical paths. Three light paths may be employed to provide an optical AND gate while two light paths can be arranged to provide an optical OR gate.

Abstract: A passive frequency-selective optical coupler comprises first and second dielectric waveguides disposed in proximate (preferably parallel) spatial disposition relative to each other. A phase propagation constant at a known frequency is common to guided modes of both dielectric waveguides while the phase propagation constants of the guided modes at all other frequencies are different. The portion of the waveguides which are arranged in proximate spatial disposition extends over a sufficient length for selectively coupling light energy between the two dielectric waveguides at the known frequency only, without coupling a significant amount of light energy at any other frequencies.

Abstract: A device for producing intensity-modulated light over a broad frequency range comprising a frequency tunable light soruce, a control line for controlling the frequency of the light source to provide a first frequency at a first time and a second frequency at a second time, and an interferometer with a differential path length. The interferometer functions to recouple the light frequencies after propagating along different interferometer paths to effect a frequency beating. The resulting beat frequency is the intensity-modulated light.

Abstract: Two interferometric electro-optic modulators formed from single mode waveguides in a single crystal substrate of pockels (linear) electro-optic material is used in conjunction with optical sampling techniques and conventional Analog-to-Digital technology to convert analog signals to a binary representation.