Abstract: An optical structure comprising a multiplicity of optical channels crossing in a plane, constructed to provide high interchannel isolation with low optical signal attenuation. Each channel possesses a refractive index that is greater than the refractive index of the encompassing planar material and is separated from the optical channel interaction region by an optical propagating material, having a refractive index that is less than the refractive index of the optical channels, which is inserted along each border between the optical channels and the channel interaction region formed by the crossover. Other embodiments of the invention provide low loss optical channel bends and a high isolation, low loss, double pole, double throw optical channel switch.

Abstract: A method and apparatus for rapidly changing the spatial modulation imposed on a stationary light beam to conform to a preselected one of a multiplicity of discrete character symbols. Automatic orientation tracking is provided which establishes a fixed direction for the spatially modulated light beam that is independent of the character accessed and provides a fixed position for the character image. The technique may be employed in electrographic high speed printers and has particular utility when used with standard character generating template masks for character generation, though it is also effective when employed with a holographic generating mask array.

Abstract: An optical repeater combines the functions of a passive star coupler and a signal regenerating amplifier. A divergence corrective device provides a means with which to more effectively utilize the optical energy radiated from a light emitting diode included in the signal regenerating amplifier. This increase in efficiency allows for the coupling of as much optical energy to each optical receiver of a multiplicity of optical receivers as would be coupled to a single optical receiver in a simple point-to-point link.

Abstract: A structure for electro-optic channeling of multimode light radiated from multimode fiber optic waveguides is disclosed. The light is channeled in a planar optic waveguide comprised of a high index electro-optic material to which the fiber optic waveguide is non-normal butt coupled to achieve higher in-plane collimation and greater confinement of divergent light beams with lower control voltages.

Abstract: An optical communication system is disclosed wherein a multiplicity of stations in a linear, random, or grid arrangement are coupled in a party-line type network in which optical signals originated by a master or responding station are relayed from station to station. Coupling between stations may be accomplished by means of optical lenses, the focal regions of which are coupled to electronic equipments that may be remotely located therefrom. This electronic equipment detects received optical signals, regenerates and retransmits these received optical signals, and originates a responding optical signal to the master station when the received optical signal is addressed to the receiving station.

Abstract: A signal mixer utilizing two oppositely poled diodes, coupled to provide parallel operation at high frequencies and series operation at intermediate and low frequencies. This arrangement reduces the number of signals generated by the mixing process with a concomitant increase in conversion efficiency for the desired mixer output signal.

Abstract: A video processor for a track-while-scan radar system, wherein each radar return, within a tracking window, is given a range weight corresponding to the range bin within the range sweep and an angle weight corresponding to a sweep count, which is initiated at the commencement of the tracking window. The weights for each return are summed to obtain a range weighted sum and an angle weighted sum, each sum then being coupled to a computer along with the total number of radar returns recorded within the tracking window. The video processor, on information supplied by the computer, establishes an annular ring about the radar system within which radar returns are sought.

Abstract: An electronic docking system utilizing a multiplicity of sensing subsystems to derive and display docking parameters during the docking operation is disclosed. The parameters displayed include bow and stern velocities ship's velocity perpendicular and parallel to the jetty and ship's orientation to the jetty during the docking maneuver. Parameters are derived from data gathered by sensors that include a receive only monopulse and a receive only doppler system which determine the angular position of a selected reference location aboard the ship and a signal with a frequency representative of the ship's velocity from a signal radiated from a beacon antenna aboard the ship. Range measurements are accomplished by utilizing baseband pulse radar systems capable of determining range to accuracies in the order of one foot.

Abstract: An apparatus for processing acoustic signals wherein an array of discrete scatterers on a substrate reflect an incident acoustic surface wave on the substrate in accordance with a predetermined transfer function which is established by the size and spacing of the scatterers within the array. The scatterers, and input and output transducers, may all be metalized on the surface of the substrate with a single mask, thus providing an economical means of construction.

Abstract: A limiter circuit is installed in a servomechanism that establishes a signal at the output terminal of a filter contained therein, in the absence of an input signal within the lock range of the servomechanism, in a manner that maintains the charge on the filter consistent with the established output signal, thus providing favorable initial conditions for rapid reacquisition and smooth reacquisition transients.

Abstract: An apparatus for coupling digital data from a data generator to a readout device and providing electrical isolation therebetween. The apparatus including a control signal generator which couples digital data, representative of the data from the data generator, to a switch which responds thereto and couples data representative thereof to an isolation device. Operation of the switch is performed without external voltage supplies, all switching being accomplished entirely with the voltages coupled from the control signal generator to the switch. The isolation device converts the electrical signals to light signals that are then coupled to a light sensitive device which converts the light signals to digital electrical signals for coupling to the readout device.

Abstract: A navigation system in which a transmitter-antenna combination radiates two independent signals with a known frequency separation there between. These signals are radiated to an antenna on a navigation marker whereby they are received and directed to a non-linear device in which signals at the fundamental frequencies and frequencies that are linear combinations of the two fundamental frequencies are generated. These generated signals are then guided to the antenna and retro-directively re-radiated. The re-radiated signals are received by an antenna at the transmitting location and directed to a receiver wherein the fundamental frequencies and the desired linear combination thereof are detected and processed to provide the locations and identification of the navigation markers.

Abstract: A geothermal well power-generation system is monitored by sensors permanently associated with the operating power generation system. These sensors detect changes in well water temperature, water pressure below and above the pump, and pump rotating speed. The data obtained is transmitted to a receiver at the earth's surface via sections of the system's plumbing which are utilized as an electromagnetic transmission line.

Abstract: An optical coupling apparatus having first and second optical waveguides wherein optical signals are coupled therebetween in a distributive manner. The distributive coupling provides essentially equally distributed optical signals in the secondary guide while maintaining an essentially continuous flow of light in the primary guide.

Abstract: An apparatus for extracting signals, proportional to data relative to a given variable, from two data modulated signals which mutually define the variable. Each signal is followed-up with a linear integrate/clamp circuit, the outputs of which are cross multiplied with the input signals. The multiplier output signals are summed and appropriately shaped to provide an output signal that is proportional to the desired angular rate.

Abstract: A system for achieving improved angular resolution with baseband radar systems which includes dual baseband receivers and a correlator or tapped transmission line therebetween. The tap on the transmission line at which pulses received by each receiver coalesce determines the angular location of a target with an angular resolution that is proportional to the ratio of the pulse width to the receiver separation.

Abstract: Apparatus for convolving acoustic surface waves without dispersion comprising a piezoelectric substrate having surface acoustic waves generated at opposite ends thereof and directed towards an interaction region formed from a semiconductor film deposited thereon. The film is deposited on the substrate at such an angle with respect to the direction of propagation of each of the two acoustic surface waves so that the dispersive components of the wave vectors associated with the surface acoustic waves refracted in the interaction region substantially cancel. Apparatus is also disclosed for substantially eliminating undesired wave reflections in a convolver operating in the degenerate mode wherein a conductive array of electrode fingers is disposed at an angle with respect to the direction of propagation of the acoustic surface waves such that the reflections therefrom are directed away from the paths traversed by said acoustic surface waves.

Abstract: A low crosstalk optical switching matrix of individual optical switches wherein anyone of n input ports may be addressed to any one of n output ports. Ports of the individual optical switches which are employed for inter-row and inter-column coupling at the interior of the matrix are not used in the last row and column and are terminated with optical signal absorbers thereat, thus providing a means for absorbing non-addressed signals and spurious reflections. The crosstalk properties of the matrix are further improved by utilizing a multiplicity of four port switching elements in tandem for each individual optical switch.

Abstract: A video detector wherein the ratio of the energy contained in a range cell of interest to the average energy contained in adjacent range cells is obtained. When the two ratios are both greater than a predetermined value, a hit is recorded. After a number of transmitted pulses, the hits obtained in the range cell of interest are summed and a target report is given when this sum is equal to or exceeds a specified value.

Abstract: A method and apparatus for measuring the level and dielectric constant of a liquid which includes a device for generating a subnanosecond baseband pulse that propagates through a transition device to a single wire transmission line that extends through an air filled region into the liquid. A discontinuity created at the air liquid interface produces a reflection of the baseband pulse that is compared with the transmitted pulse with respect to time of arrival and amplitude to determine the liquid level and the reflection coefficient at the air liquid interface. The reflection coefficient is then utilized to determine the dielectric constant of the liquid.