Abstract: In a catalytic type propane gas or organic gas detector there is provided a heater for the catalyst of the heat pipe type. One end of the heat pipe is in the flame of the standing pilot and the other end is in contact with the catalyst so that the waste heat from the pilot flame is used to maintain the catalyst at an elevated temperature.

Abstract: The present invention is directed to an ionization cell for detecting the presence of very minute concentrations of certain chemical agents. The effective sensitivity of conventional chemical agent detectors is restricted in the presence of certain interferants such as jet fuel, gasoline, smoke, turpentine and the like. Herein a "chemical bias," that is a background concentration of a simulant is provided at the inlet of an ionization detector, which chemical bias is effective by charge exchange to prevent the interferants from dominating the signal.

Abstract: A plasma polymerized ethane thin film deposited on a variety of substrates has been discovered to be an improved interlayer dielectric. It is a material having property of high dielectric strength and unique low dielectric constant. It also has advantages of depositing pinhole free, crack resistant with good step coverage and low deposition cost.

Abstract: A permalloy thin film temperature sensing element in which the NiFe film material is deposited on a substrate in very narrow lines less than about 15 .mu.m wide and in film thicknesses in excess of about 400A.degree. preferably in the range of 1600.degree.-3200A.degree..

Abstract: In a multi-burner boiler or industrial furnace installation that uses pulverized coal for fuel and utilizes an oil pilot torch it has been difficult to sense and discriminate satisfactorily between safe and unsafe burner operation in these multi-burner arrangements. By using both a Si detector (visible light responsive) and a lead sulfide detector (infrared responsive) and selectively combining the signals therefrom, the best characteristics of both detectors are utilized to provide satisfactory flame sensing.

Abstract: Hg.sub.1-x Cd.sub.x Te is an important semiconductor for use in photovoltaic and photoconductive infrared photon detectors. Hg.sub.1-x Cd.sub.x Te can be grown by liquid phase epitaxy at atmospheric pressure from a Te-rich solution in which case the Hg vapor pressure is below 0.1 atm at 500.degree. C. This low vapor pressure makes possible the use of open-tube, slider growth techniques. The present invention describes a covered graphite slider system which provides an additional source of Hg, minimizes loss of Hg from the source wafer and virtually prevents loss of Hg from the (Hg.sub.1-x Cd.sub.x).sub.1-y Te.sub.y growth solution.

Abstract: This invention pertains to an improved technique of introducing an added insulative layer between the thermoplastic layer and the photoconductive layer of the thermoplastic photoconductive holographic recording medium. The added layer (pure PVK) is electrically insulating at temperatures used for thermal development to prevent decaying charge contrast during hologram development.

Abstract: A conductivity type thin film humidity sensor on a silicon chip which sensor includes structure which electrically shields the sensing area from highly dissociative contaminants.

Abstract: An optical system for creating the ambiguity function of a moving target is disclosed. The two signals which are to be used in the analysis are coded on spatial data masks as two-dimensional arrays of one-dimensional functions. The frequency scaling property of a post lens Fourier Transform is utilized to apply a variable scaling factor to at least one of the functions. This is accomplished by passing a beam of substantially coherent light through a cylindrical Fourier Transform lens before it passes through the data masks. At least one of the data masks is then set at an angle other than perpendicular to the beam path.

Abstract: A humidity sensor having an extended impedance range extending up to 10.sup.12 ohms precludes leakage currents. The sensor is in the form of an insulating substrate having conductive film such as gold applied to a surface thereof. The perimeter of a first film is completely encompassed by but spaced from a second film on the surface of the substrate. A humidity responsive layer of iron oxide is applied over the film layers to bridge the spacing therebetween in a continuous manner. Electrical terminals are connected, respectively, to the two films to provide a readout in terms of humidity.

Abstract: The present invention is directed to a process for complex, high density microcircuits in which thick film dielectric pastes are photolithography patterned into high resolution stencils to produce complementary conductor circuitry patterns, the voids of the developed dielectric stencil are filled with thick film conductor paste, and then there is a cofiring of the conductor and the dielectric. With this new process the number of separate firing operations is reduced. The reduction in the number of firings is important in multilevel hybrid structures.

Abstract: A process for fabricating aluminum nitride needles, the process utilizing moderate furnace temperatures (950.degree. C.-1000.degree. C.) and low toxicity reactants (i.e. NH.sub.3 and Al). Argon gas and ammonia gas are mixed and flowed over the heated aluminum and the aluminum nitride needles grow at the upstream end of the hot zone of the furnace.

Abstract: In an optical absorption gas sensor there is a practical problem of obtaining a sufficiently long optical path necessary to provide the required sensitivity within a compact space. In the present invention the path length can be multiplied to about 2 meters in a hemispheric like chamber having a radius about 8 cm. A novel, compact and inexpensive cell structure for increasing the optical path length by multiple reflections is provided.

Abstract: Hg.sub.1-x Cd.sub.x Te is an important semiconductor for use in photovoltaic and photoconductive infrared photon detectors. Hg.sub.1-x Cd.sub.x Te can be grown by liquid phase epitaxy at atmospheric pressure from a Te-rich solution in which case the Hg vapor pressure is below 0.1 atm at 500.degree. C. This low vapor pressure makes possible the use of open-tube, slider growth techniques. The present invention describes a covered graphite slider system which provides an additional source of Hg, minimizes loss of Hg from the source wafer and virtually prevents loss of Hg from the (Hg.sub.1-x Cd.sub.x).sub.1-y Te.sub.y growth solution.

Abstract: Apparatus for determining the composition of mercury-cadmium-telluride or other alloy semiconductors by using a four-photon mixing phenomenon. Means are provided for a pair of colinear laser beams of different optical frequencies such that the colinear beams passed through a sample of Hg.sub.1-x Cd.sub.x Te or other alloy semiconductors to produce emissions beams of the original incident optical frequencies and two or more additional optical frequencies formed by an electron spin-flip interaction. A magnetic field means is employed for varying a magnetic field across the sample during passage of the colinear beam from the points substantially below to substantially above the resonant field of the sample to produce a spin-flip signal which has a peak amplitude. Detector means are adapted to receive the emission beams to identify the spin-flip signal peak from which the spin-level splitting factor can be measured. Upon measurement of the spin-level splitting factor, the value for x can be calculated in Hg.sub.

Abstract: An optical system which computes the ambiguity integral using one-dimensional spatial light modulators rather than the two-dimensional data masks or spatial light modulators used in the prior art is revealed. The coding is accomplished by compressing the light beam along one dimension, passing it through a one-dimensional spatial light modulator, and re-expanding the beam along the compressed dimension. The signal may be rotated to produce a linear dependence. In the preferred embodiment an acousto-optic cell commonly known as a Bragg cell is the one-dimensional spatial light modulator chosen.

Abstract: An intruder alarm for protecting the perimeter of an area utilizes a multimode optic fiber as the deformable sensing element, wherein a length of multimode optic fiber is buried in the ground of an area or perimeter to be protected. As coherent light from a laser is directed through a length of optic fiber, the output light pattern therefrom is speckled. When a deformation of the fiber occurs, even a small amount, the speckle pattern changes and is detected electronically indicating that a disturbance has taken place.

Abstract: In a thermoplastic-photoconductor holographic recording medium in the form of several transparent layers over a transparent substrate, such as an optically transparent electrically conductive layer, then a photoconductor layer and a thermoplastic layer over such as glass or Mylar, a conventional material such as gold or platinum has been used as a transparent conductive layer. It is desired to use a less precious metal such as nickel-chromium (NiCr) as the conductive layer, however a limitation has been found in that an unwanted dark charge injection occurs from the NiCr to the photoconductive layer. This causes poor charge acceptance and therefore results in poor halogram formation. Herein a mono atom thick layer of the NiCr is treated and becomes on oxide layer which forms an effective charge blocking layer to dark charge injection.

Abstract: Charge leakage can occur at a photoconductor-conductor electrode interface of a thermoplastic photoconductive holographic recording medium. This reduces the charge contrast and causes poor performance of the thermoplastic-photoconductive device. In the present invention there is provided a blocking layer of polyvinyl alcohol or polyvinyl butyral between the conductive layer and the photoconductive layer.

Abstract: A method of growing single crystals of silicon doped with thallium for use as an extrinsic silicon photodetector of 3-5 um infrared radiation which will operate above 77 K.