Abstract: This invention pertains to a method and apparatus for inscribing a pattern into a surface of a substrate, such as a sheet of glass. The method includes the steps of providing a Nd:YAG laser (12) having a characteristic output wavelength of 1.06 micrometers; providing a glass substrate (18) that is substantially transparent to the characteristic output wavelength; and applying a layer of material, such as a layer of tape (16), to a surface (18a) of the substrate. The layer of material is selected so as to strongly absorb the characteristic output wavelength. A next step focuses (14) an output of the laser into a spot (12c) at or near to an interface between the layer of material and the surface of the substrate. A further step translates (20) the surface relative to the spot. The layer of material absorbs the output of the laser and is heated thereby to a temperature sufficient for inscribing the surface underlying the spot.

Abstract: A microelectronic device includes a substrate device and a dark mirror coating overlying one side of the substrate device. The dark mirror coating has a via therethrough to the substrate device. The dark mirror coating has a plurality of alternating layers of dielectrics and metals. Each metallic layer has an electrically nonconducting region adjacent to the vias, preferably formed by anodizing the metallic layers after deposition.

Abstract: A Clock and Bias Module (CBM 10) includes a low pass filter speed-up switch (U104, U114) to provide both a long time constant and fast settling; bootstrapped power supplies (VR101-104) to provide a wide, programmable output voltage range with overload protection; an integrating output driver (20) to provide controlled clock slew rates while maintaining a precision rail voltage; an active current steering bridge (Q5, Q6, CR1, CR2) to allow computer programmable control of slew rates; a current measurement circuit (U14, U15, U19) that enables sensing an average load current in the presence of large voltage swings; and a compact modular implementation that allows for close proximity of the circuitry to a unit under test. The CBM provides IR Detector FPA electrical stimulus in an automated testing environment. The clock generation circuitry is fully programmable for rail voltage, rising slew rate, and falling slew rate.

Abstract: A gold-coated molybdenum article (30) is made by furnishing a substrate (32) made of pure molybdenum or an alloy of molybdenum, and preparing a slurry of gold powder, acrylic binder, and acetone liquid carrier. The slurry is applied to a portion of a surface of the substrate. The substrate with applied slurry is heated in vacuum or inert atmosphere to an elevated temperature, preferably about 2040.degree. F., and thereafter cooled to ambient temperature. The result is an article (30) having at least a portion of the substrate (32) covered with an adherent gold coating (34).

Abstract: An optical device assembly includes a planar optical filter and a planar sensor having an optically active area. The optical filter and the sensor are joined together with a gap therebetween by a standoff structure extending between the optical filter and the sensor. The standoff structure is positioned at a location outside of the optically active area of the planar sensor. The standoff structure includes a standoff element, a first bonding element between the standoff and the filter, and a second bonding element between the standoff and the sensor. The two bonding elements each preferably comprise a cold-weldable indium bump. If the standoff structure, the filter, or the sensor is made of a material to which indium does not readily cold weld, a bonding pad of a material such as titanium/nickel can be inserted to facilitate the cold welding.

Abstract: A solid state array has a plurality of radiation detector unit cells, wherein each unit cell includes a bias-selectable two color photodetector in combination with either a second bias-selectable two color detector (10, 11) or a single photodetector (10', 11'). Each unit cell is thus capable of simultaneously outputting charge carriers resulting from the absorption of electromagnetic radiation within two spectral bands that are selected from one of four spectral bands and three spectral bands.

Abstract: A responsivity calibration system for use with an array of detectors. The system includes a first mechanism for changing the orientation of the detector array from the first orientation, during an operational mode, to a second orientation, during a calibration mode, in which each detector sequentially samples the same portion of the same scene. The system adjusts the output generated by each of the detectors in the first orientation in response to an associated signal generated by that respective detector in the second orientation. In a specific implementation, a normalization factor is generated based on the output of each detector during the calibration mode. The normalization factor is stored and multiplied by the outputs of the detectors during the operational mode. Hence responsivity correction is implemented without the need for a wide area scene of extreme uniformity or an on-board target.

Abstract: A vacuum system (20) includes an enclosure (22) having a vacuum-tight wall (26) and an internally threaded aperture (66) through the wall (26). A tip-off fitting (24) has a base (50) with a bore (52) therethrough, a hollow tube (62) fixed to the base (50) with a vacuum-tight seal, such that an interior (64) of the tube (62) is in communication with the bore (52) in the base (50), and an external thread (58) on the exterior of the base (50). The external thread (58) on the exterior of the base (50) is dimensioned to threadably engage the internal thread (68) on the aperture (66). There is a disengageable vacuum sealant (70) such as a layer of indium metal between the external thread (58) of the base (50) and the internal thread (68) of the aperture (66). The vacuum system (20) is evacuated through the tip-off fitting (24) and sealed by closing off the hollow tube (62).

Abstract: A differential spectrometry system detects very narrow-band spectral features, while providing much higher optical transmittance and signal-to-noise ratios than prior optical-filter-based spectrometer systems. A plurality of light detectors (10a, 10b) detect light that falls within respective wide wavebands. The wide wavebands have overlapping and non-overlapping portions, one of which is the desired narrow waveband. The detector outputs are operated upon to produce an output signal (22) which includes substantially only the desired narrow waveband. In the preferred embodiment, the light detectors (10a, 10b) are implemented with a pair of optical detectors (30a, 30b) and respective optical interference filters (24a, 24b). The filters have substantially identical cut-off wavelengths (.lambda..sub.2) and cut-on wavelengths that are shifted by .DELTA..lambda. with respect to each other (.lambda..sub.1 and (.lambda..sub.1 +.DELTA..lambda.), respectively).

Abstract: A highly integrated thermal sensor (10) is responsive to radiation having wavelengths within a predetermined band of wavelengths. The sensor, which may be a thermopile, is comprised of a substrate (16) comprised of at least one semiconductor material. The substrate includes at least one active region disposed within a first surface of the substrate. The sensor further includes a plurality of thermally-responsive junctions (HJ, CJ) between dissimilar materials (22, 24) that are disposed within the at least one active region, wherein at least one of the thermally-responsive junctions is a hot junction. The hot junction is thermally isolated from the substrate by being suspended from the substrate on dielectric bridges or, in another embodiment, by a thermally insulating and patterned polymer. In a backside illuminated embodiment of this invention the sensor further includes an optical cavity (26) formed within a second surface of the substrate in registration with the active region.

Abstract: An optical device assembly includes a planar optical filter and a planar sensor having an optically active area. The optical filter and the sensor are joined together with a gap therebetween by a metallic bump extending between the optical filter and the sensor. The metallic bump, which is preferably indium, is positioned at a location outside of the optically active area of the planar sensor. The metallic bump is preferably formed by vapor depositing an indium subbump on the optical filter and another indium subbump on the planar sensor, in each case outside of their optically active areas, and thereafter pressing the two subbumps together to complete the bonding.

Abstract: A flip-chip assembly and method for reducing the stress in its metal interconnections resulting from thermal mismatch includes a detector that has a radiation sensitive circuit on a substrate that is flip-chip connected to a layer of semiconductor material that is provided with a readout circuit. The substrate has a thermal coefficient of expansion (TCE) greater than the semiconductor layer such that operating the detector over a predetermined temperature range would stress the flip-chip connections. A first compensation layer on the readout chip has a TCE greater than the substrate's, and a second compensation layer on the first layer has a TCE approximately equal to the semiconductor layer's. The materials and thicknesses of the compensation layers are selected such that the TCE of a composite structure that includes the semiconductor and compensation layers is approximately equal to the substrate's TCE to avoid the stress over the predetermined temperature range.

Abstract: Methods are disclosed for fabricating a monolithic array of radiation detectors and associated readout circuits, as are monolithic arrays fabricated by the methods.

Abstract: An integrated photovoltaic detector includes a reference photovoltaic detector and an active photovoltaic detector in a series connection. The reference detector produces a dark current that opposes the active detector's dark current. The active detector effectively masks the reference detector from incident illumination so that the active detector produces photocurrent but the reference detector does not. The band gap of the reference detector is preferably matched to the active detector so that their dark currents are substantially matched over a temperature range. As a result, the current read out of the integrated detector at the series connection is approximately equal to the photocurrent generated by the active detector. This improves the detector's SNR, signal resolution, and useful operating temperature range.

Abstract: A photoresponsive device (10) includes a body comprised of semiconductor material comprised of elements selected from Group IIB-VIA; and at least one electrically conductive contact pad (20) formed over a surface of the semiconductor material. The at least one electrically conductive contact pad is comprised of metal nitride, such as MoN, and serves as a diffusion barrier between an Indium bump (22a, 22b) and the underlying semiconductor material. A passivation layer (18), such as a layer of wider bandgap CdTe, can be formed to overlie the surface of said semiconductor material. A p-n junction is contained within a mesa structure (10a) that comprises a portion of an n-type base layer (14) and a p-type cap layer (16). A first contact pad is disposed over the cap layer and a second contact pad is disposed over the base layer.

Abstract: The light receiving or back-side surface (22) of an indium antimonide (InSb) photodetector device (10) substrate (12) is cleaned to remove all native oxides of indium and antimony therefrom. A passivation layer (26) is then formed on the surface (22) of a material such as silicon dioxide, silicon suboxide and/or silicon nitride which does not react with InSb to form a structure which would have carrier traps therein and cause flashing. The device (10) is capable of detecting radiation over a continuous spectral range including the infrared, visible and ultraviolet regions.

Abstract: An optical coupler for coupling energy from a laser diode bar is disclosed. The coupler includes multiple rectangular optical fibers that each have a cylindrical lens which is an integral part of each fiber end. The fiber ends are held in a fixed spatial relationship by a retainer. In one coupler embodiment, each fiber end is shaped to define the cylindrical lens. In another coupler embodiment, each fiber end carries a lens shaped from an optical medium. Methods of making the couplers are also disclosed.

Abstract: A three terminal solid-state ionizing radiation detector (10) includes a first layer (18) of a substantially intrinsic Group II-VI compound semiconductor material, such as CdZnTe. The first layer is responsive to incident ionizing radiation for generating electron-hole pairs. The detector further includes a second layer (24) of Group II-VI compound semiconductor material and a third layer (20) of Group II-VI compound semiconductor material that is interposed between first surfaces of the first layer and the second layer. The third layer functions as a grid layer. A first electrical contact (12, 17) is coupled to a second surface of the first layer, a second electrical contact (29, 30) is coupled to a second surface of the second layer, and a third electrical contact (22) is coupled to the third layer for connecting the detector to an external circuit that establishes an electric field across the detector.

Abstract: A differential spectrometry system detects very narrow-band spectral features, while providing much higher optical transmittance and signal-to-noise ratios than prior optical-filter-based spectrometer systems. A plurality of light detectors (10a, 10b) detect light that falls within respective wide wavebands. The wide wavebands have overlapping and non-overlapping portions, one of which is the desired narrow waveband. The detector outputs are operated upon to produce an output signal (22) which includes substantially only the desired narrow waveband. In the preferred embodiment, the light detectors (10a, 10b) are implemented with a pair of optical detectors (30a, 30b) and respective optical interference filters (24a, 24b). The filters have substantially identical cut-off wavelengths (.lambda..sub.2) and cut-on wavelengths that are shifted by .DELTA..lambda. with respect to each other (.lambda..sub.1 and (.lambda..sub.1 +.DELTA..lambda.), respectively).

Abstract: Gamma ray detectors (20, 130) are provided with a detector layer (30) that is formed of Hg.sub.x Cd.sub.1-x-y Zn.sub.y Te, wherein 0<x<0.05 and 0.ltoreq.y<0.5. The Hg percentage in the group II sublattice of this detector layer is limited to replace Cd vacancies. These Cd vacancies are native point defects which degrade the resolution of gamma ray detectors because they facilitate early electron-hole recombination and time delays of current carriers.