Abstract: A muitilayer microelectronic photomultiplier device is fabricated by disce procedures to provide a photocathodeanode and dynode chain arrangement which is analogous in operation to conventional photomultiplier tubes. This multilayer microelectronic photomultiplier device provides for low level photon detection and realizes the advantages of high reliability, small size and fast response, plus lower cost, weight and power consumption compared to conventional photomultiplier tubes. In addition, the fabrication on an SOI substrate permits integration of logic and control circuitry with detectors. The insulating substrate also permits the integration of an on-chip high voltage supply and may easily be extended to a plurality of detectors with high packing densities due to the inherently stacked geometry offering improved performance and design flexibility.

Abstract: A control system for a remotely controlled vehicle comprises a supervisory control system which receives supervisory speed and turn rate commands from a human operator which are provided to a servo-controlled vehicle; an obstruction detection system having multiple sensors mounted to the vehicle detect any obstructions in the path of the vehicle; and a collision avoidance control system coupled to the supervisory control system, the obstruction detection system, and to the vehicle. The collision avoidance control system disables the supervisory speed and turn rate commands when the obstruction detection system detects an obstruction. The collision avoidance control system also generates and provides obstacle avoidance speed and turn rate commands to the vehicle to direct the vehicle to avoid obstruction in the path of the vehicle, and enables the supervisory speed and turn rate commands after the obstruction is avoided so that control of the vehicle is returned to the human operator.

Abstract: A method for fabricating complementary enhancement and depletion mode field ffect transistors on a single substrate comprises the steps of: a) patterning a structure of a layer of silicon formed on an insulating substrate to form first, second, third, and fourth silicon islands; b) doping the second island with a p-type dopant; c) doping the third island with a p-type dopant; d) doping the fourth island with an n-type dopant; e) forming a first electrically insulating gate layer on the third and fourth islands; f) forming a second electrically insulating gate on the first and second islands; g) forming an electrically conductive gate over the first and second electrically insulating gate layers; h) doping the second island with an n-type dopant; i) doping the fourth island with an n-type dopant; j) doping the first and third islands with a p-type dopant; and k) doping the first and third islands with a p-type dopant to transform the first island into a p-type enhancement mode field effect transistor, the seco

Abstract: A system enables omnidirectional non-line-of-sight simultaneous communicans in a number of frequency separated channels in the ultraviolet spectrum. A plurality of discharge lamps each has at least a single different isotope of mercury for each omnidirectionally radiating a discrete line in the ultraviolet spectrum. Each of the discrete lines in the ultraviolet spectrum is modulated by an on-off sequence generator so that modulated discrete lines transmit communications to a number of receivers randomly disposed in a non-line-of-sight relationship to the discharge lamps. Aborption filters at each receiver contain a quenching gas and all the other isotopes of mercury except the one which generated the modulated discrete line of interest.

Abstract: The invention includes a data memory having sequentially stored N-bit words that are each a binary description of a time at which an event is to occur. Also stored is a K-bit word, associated with each N-bit word, that is a binary description of what the scheduled event is to be. The invention utilizes a free-running clock and clock circuitry to gauge when an event should occur. The clock circuitry tallies an N-bit description of running time. M-bits of the N-bit description of running time are specified by a single fast synchronous counter. The remaining N-M bits are specified by two slow counters each of N-M bit capacity. Because incrementation of slow counters creates count settling times that may significantly affect accurate event sequencing, the slow counters are alternately incremented and a multiplexer is used to switch to the counter that will provide a "steady state" count at a scheduled event time.

Abstract: A multisignal combiner is provided for weighting the best performing signal of an amplitude transform signal and a phase difference transform signal produced by a processor which receives a two dimensional signal and has intermediate signals which are a variance of the amplitude and a variance of the phase difference of the received signal. A device is provided for receiving the variance of the amplitude and the variance of the phase difference for producing a pair of weighting factors, each of which is inversely proportional to the size of the variances of the respective values, and a third weighting factor which is 1 minus the weighting factor of the signal which has the smallest variance. The transformed signals are weighted by the weighting factors and the received signal is weighted by the third weighting factor. The weighted signals are then summed to provide a final output signal which has it's best performing signal component enhanced relative to the other signal components.

Abstract: Efficient, low threshold laser emission from a laser crystal doped with chromium and neodymium ions is obtained when pumped by visible laser diodes in the range of 610 nm to 680 nm. A typical laser Cr,Nd:GSGG crystal having an extraordinarily broad absorption bandwidth allows high pump efficiencies when using visible laser diodes, particularly in comparison to the Nd:YAG laser. The broad absorption bandwidth tolerance of the Cr,Nd:GSGG crystal to the pumping wavelengths allows visible diode pumping of the neodymium transition without regard to the wavelength of the visible diodes. Longitudinal or end-pumping to take advantage of the emission properties of the visible laser diodes, a nearly hemispherical laser resonator configuration and other co-doped Cr,Nd laser host materials are disclosed. Consequently, costs are reduced for the semiconductor pump as well as producing a compact, efficient, lightweight and reliable laser previously unachievable with other types of laser or lamp pumping.

Abstract: An improved crossbar switch in which internal buffering is performed for input signals across the chip and in which an extra input for each output channel of the crossbar switch element is provided.

Abstract: A tunable solid state laser produces a laser emission at one or more wavelengths simultaneously. The tunable solid state laser includes a laser resonator defined by an output coupler reflective element, two fold mirrors, and one or more high reflectivity end elements to form a reflective path in a laser resonator cavity therebetween with a laser crystal disposed in the laser resonator cavity. A means for optically exciting the laser crystal is appropriately disposed for end pumping the laser crystal to produce a laser emission in a predetermined range of wavelengths. A wavelength dispersing element such as a prism is disposed in the laser resonator cavity between one of the fold mirrors and the high reflectivity end elements for tuning the laser emission at one or more of the desired wavelengths in the predetermined range of wavelengths, the dispersing element being transparent to the laser emission over the predetermined range of wavelengths.

Abstract: A cost-effective, producible improved apparatus for and method of fabricag a transducer acoustic window for a marine environment has acceptable acoustic energy transmitting properties and appropriate mechanical properties to withstand the rigors associated with varying velocities of flowing water, fluctuating temperatures, changing ambient pressures, the abuse attendant operations, etc., that are routinely encountered during a prolonged deployment. The acoustic window has a cast CONAP 1556 polyurethane window portion that extends over a hull opening and on a bearing surface rim about the opening. A number of equidistantly, circumferentially spaced stainless steel inserts are molded in the cast polyurethane window portion. Each of the inserts has a threaded outer surface, a machined flat, a longitudinal slot and a countersunk unthreaded bore and each threaded outer surface, machined flat and longitudinal slot mechanically engage the cast polyurethane window portion in an adhering and bonding relationship.

Abstract: A system of navigational referencing for a robot moving within a defined space is provided. A database contains x-y coordinate positional information on a plurality of doorway openings in terms of an x-y coordinate system. A mobile robot is provided that has the capability to access the database, define its location in terms of an approximate position within the defined space, and sense the presence of one of the plurality of doorway openings. The robot is positioned and moved along a path that traverses the one doorway opening at a known speed. The doorway opening's top door frame is detected from first and second sensor positions on the robot. The first and second sensor positions are separated by a known distance along a line orthogonal to the path that traverses the one doorway opening.

Abstract: A steering simulation device provides torsional resistance and a "center urn" function to a remote control steering mechanism experiencing bidirectional (clockwise or counterclockwise) rotational movement. A compact design is provided by utilizing a series of rotationally elastic couplings that permit (1) an adjustable turning resistance, (torsional resistance), (2) an adjustable, bidirectional rotary range (clockwise or counterclockwise), and (3) a self-centering capability.

Abstract: A structure for modulating electrostatic potential in the vicinity of a surface of a structure comprises: a substrate; a first electrically conductive layer having an exposed surface and made of a first electrically conducive material formed on the subrate, the first electrically conductive material disposed to being transformed into an electrically insulting material; an electrically insulating layer formed on the surface of the first layer from the first electrically conducive material; and a second layer of a second electrically conductive material formed on the substrate and contiguous with the insulating layer so that a voltage potential between said first and second layers provides an electrostatic interaction with the substrate.

Abstract: A transceiver has a transmitter portion using serially coupled FETs coupled o low level positive and negative bias sources to enable a low power drain conversion of TTL input signals to low level serial data output signals for a coaxial data transmission cable and vice versa The transceiver also provides a constant 50 ohm impedance for the coaxial or triaxial transmission cable during active transmission periods, stand-by periods and power-off periods to provide an inexpensive method to transmit and receive 10 Megabit coded data via a coaxial or triaxial cable.

Abstract: A method determines the concentration of a chemical of interest in a solution. A permeable membrane is placed in the solution and a ligand is exuded through the membrane to continually renew the ligand at the surface of the membrane which is in contact with the solution. Complexes of the ligand with the chemicals of interest are formed where the ligand renewed membrane is in contact with the solution. Illuminating the ligand renewed membrane with radiation from a distance from the membrane induces a fluorescence by the formed complexes on the ligand renewed membrane by the illuminating radiation. The fluorescence from the illuminated complexes on the ligand renewed membrane are detected from a distance from the membrane to provide a determination of the concentration of the chemical of interest in the solution.

Abstract: STATEMENT OF GOVERNMENT INTERESTThe invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

Abstract: A microelectronic photomultiplier device is fabricated by discrete proceds to provide a photocathode-anode and dynode chain arrangement which is analogous in operation to conventional photomultiplier tubes. This microelectronic photomultiplier device provides for low level photon detection and realizes the advantages of high reliability, small size and fast response, plus lower cost, weight and power consumption compared to conventional photomultiplier tubes. In addition, the fabrication on an SOI substrate permits integration of logic and control circuitry with detectors. The insulating substrate also permits the integration of an on-chip high voltage supply and may easily be extended to a plurality of detectors offering improved performance and design flexibility.

Abstract: A turn-on transient overcurrent response suppressor is connected to an exing electrical circuit having a regulator circuit that includes an overcurrent protection mechanism. A first charging circuit is connected to the power supply for simultaneous charging therewith. A second charging circuit is connected to the first charging circuit for delayed charging therewith. Connected between the first and second charging circuits is a circuit to create a low impedance discharge path for the second charging circuit while preventing discharge of the first charging circuit when the power supply is no longer providing the input voltage. First and second transistor circuits are connected to turn on during the charging and discharging of the second charging circuit and turn off when the second charging circuit is fully charged. In this way, turn-on transients caused by loss of AC power are prevented from falsely triggering the regulator circuit's overcurrent protection mechanism.

Abstract: An apparatus is provided for identifying an unknown liquid by determining the speed of sound in the liquid. A pulse generator provides an excitation pulse to a first acoustic transducer which transmits an acoustic pulse in the liquid. The acoustic pulse is received by a second acoustic transducer at a distance from the first transducer measured by a displacement transducer. A gated clock is enabled by the excitation pulse and disabled when the acoustic pulse received by the second acoustic transducer reaches a predetermined threshold. The clock measures the time it takes the acoustic pulse to travel the distance between transducers. The temperature of the liquid is determined by indirect means and is provided as an input to a digital computer which computes the speed of the acoustic pulse by dividing the distance between the transducers, provided by the displacement transducer, by the elapsed time measured by the clock.

Abstract: A field effect transistor comprises a diamond substrate which has a p-type ion implanted region coterminous with a surface of the diamond substrate, wherein the ion implanted region has a hole concentration in the range of 1.times.10.sup.15 to 1.times.10.sup.17 holes/cm.sup.2, and a hole mobility equal to or greater than 1 cm.sup.2 /V-sec; spaced apart source and drain electrodes formed over the p-type ion implanted region on the surface of the diamond substrate; an electrically insulating material formed over the p-type ion implanted region on the surface of the diamond substrate between the source and drain electrodes; and a gate electrode formed on the surface of the insulating material.