Abstract: A leadscrew mechanical drive includes a leadscrew having a leadscrew axis and a leadscrew thread with a nonzero leadscrew thread pitch. A leadscrew follower structure is engaged to the leadscrew. The leadscrew follower structure includes a first leadscrew follower and, desirably, a second leadscrew follower. The first leadscrew follower and the second leadscrew follower are substantially identical, and each leadscrew follower includes a threaded insert having an insert thread with a nonzero insert thread pitch different from the leadscrew thread pitch. The insert thread is engaged to the leadscrew thread over a circumferential distance of less than one-half turn of the insert thread.

Abstract: A radiation sensor (20) has a substrate (34); an antenna (24) coupled to the substrate (34), a thermal detector unit TDU (22) spaced from the antenna (24) and the substrate (34); and a multi-layered conductive lead (30). The conductive lead (30) physically contacts the antenna (24) and the TDU (22). The conductive lead (30) defines a support layer (44) adjacent to the substrate (34) for structurally supporting the TDU (22) over a cavity defined by the substrate (34), a buffer layer (46) disposed on the support layer (44), and a superconductive layer (48) disposed on the buffer layer (46). The buffer layer has a crystalline structure to facilitate bonding with other layers. A method for making the sensor (20) is disclosed wherein the superconductive layer (48) and the buffer layer (46) are deposited using laser deposit, the buffer layer (46) with ion beam assist for alignment.

Abstract: An electron-beam deposition system includes an evaporation source having a source target with a target location at which a deposition material may be positioned, and a controllable electron-beam source disposed to direct an electron beam at the target location. A trailing-indicator monitor measures a past evaporation performance of the evaporation source and has a trailing-indicator output, and a leading-indicator monitor measures a future evaporation performance of the evaporation source and has a leading-indicator output. A controller receives the trailing-indicator output and the leading-indicator output, and controls the electron-beam source responsive to the trailing-indicator output and to the leading-indicator output. Preferably, the trailing-indicator monitor measures a deposition of the deposition material on a monitored substrate, and the leading-indicator monitor measures a brightness of the deposition material in the evaporation source.

Abstract: An infrared detector has a multi-layer structure to simultaneously detect IR energy in different spectral bands without changing polarity of a bias imposed across the detector. Two absorption layers are separated by a barrier layer that imposes an electrical potential barrier to one of the absorption layers. Under low bias in one direction, only one layer generates a photocurrent. Under a higher bias in the same direction, both layers generate a photocurrent. Additional absorption layers may be added to detect additional bands of energy, where the additional absorption layers generate photocurrent under a bias in another direction. Two, three, and four band detection is disclosed. Where absorbing layers within a single unit cell absorb under different bias direction, the barrier layer between those different bias direction layers suppresses a diffusing electron current. A method for detecting and resolving energy absorbed in two, three, and four different energy bands is also provided.

Abstract: A weapon sight can be mounted on a weapon. According to one aspect of the invention, the sight only presents certain information on a display if the orientation of the sight satisfies an orientation criteria.

Abstract: A weapon sight can be mounted on a weapon. According to still another aspect of the invention, the sight takes a selected action if it detects the presence of a selected color within radiation originating externally of the sight.

Abstract: An optical system includes a reflection-angle-selective mirror having a substrate, and a reflection-angle-selective coating structure deposited on the substrate. The reflection-angle-selective coating structure has a higher reflectance for light that is incident upon the reflection-angle-selective coating structure at a first incidence angle within an acceptance-angle deviation from a design incidence angle than for light that is incident upon the reflection-angle-selective coating structure at a second incidence angle greater than the acceptance-angle deviation from the design incidence angle. The optical system may also include a light source.

Abstract: Disclosed herein are apparatus and methods for measuring error associated with the rotation of bearings (50) used within a pointing device (11) on board a space-based platform. The apparatus includes inductive, or “eddy current,” proximity sensors (1000) adapted for measuring the positioning of bearing components. The apparatus also includes processing capabilities (1010) for receiving data from the proximity sensors (1000), and producing compensation data. The compensation data is used in one of various techniques for correcting errors in the angular measurement or pointing of the device (11). The techniques disclosed herein include conducting an initial calibration of the proximity sensors (1000) and generating calibration data. Once in active use, sensor measurements are combined with calibration data to produce compensation data. Ongoing measurements may be used to update the calibration data as necessary.

Abstract: An analog to digital converter ADC is adapted for low power for use in an imaging array. The ADC is a digital inverter with feedback to convert an asynchronous ramp voltage to an output count at each crossing of a voltage threshold. A separate circuit generates a voltage ramp that is coupled through a capacitor to a photocurrent from a detector, generating an integrating voltage that is raised at a source follower circuit. The integrating voltage from the source follower circuit is converted to another voltage ramp and inverted at the ADC. A global count from an array of such ADCs is stored in a grey counter. The ADC is sufficiently power-efficient that each unit cell of an array of photo detectors can have its own ADC. Circuit and device-level embodiments are disclosed.

Abstract: An optical demultiplexer includes a first light bandpass filter that receives an input light beam at a first angle of incidence, passes a first light wavelength, and reflects a reflected beam, and a second light bandpass filter that receives the reflected beam at a second angle of incidence and passes a second light wavelength. A beam redirection element such as a reflective surface receives the reflected beam from the first light bandpass filter and redirects the reflected beam toward the second light bandpass filter at the second angle of incidence.

Abstract: A radiation detector (10) has a base (30), a frame (48), a window (46), and solder layers (50, 52) formed from a solder pre-form (58, 60) to define a vacuum chamber (56). Feedthroughs (18, 40, 44) penetrate the base (30) for electrical connection to internal components. A method for sealing the detector (10) aligns a lower detector assembly (62), the frame (48) the window (46), and the solder pre-forms (58, 60) in a non-sealed relation within a processing chamber (80, 94). High temperature and low pressure is imposed, and the getter (42) is activated by resistive heating imposed by current leads (88). The window (46), frame (48), and lower detector assembly (62) are then pressed together and sealed by the liquefied solder pre-forms (58, 60). The method eliminates the need for a seal port, combines several steps within the processing chamber (80, 94), and eliminates certain prior art cleaning steps.

Abstract: A primary mirror 22 defines an active concave surface 24, a first planar 40 and a first concave 42 alignment surfaces, each facing an active surface 30 defined by a secondary mirror 28. The secondary mirror also defines a second planar 46 a second concave 48 alignment surfaces, each opposite the active surface 30. Alignment beams 64, 66, 68, 70 are reflected from each of the four alignment surfaces, which all face the same direction, to adjust the mirrors. The first planar alignment surface is used to adjust tip and tilt of the primary mirror; the first concave alignment surface is used to position a retro reflector 50 relative to the primary mirror; the second planar alignment surface is used to adjust tip and tilt of the second mirror, and the second concave alignment surface is used to adjust the second mirror in the x, y and z direction relative to the first mirror. The apparatus and method are described for two and three mirror telescopes.

Abstract: A digital projection display system includes one or more digital projection displays. Each digital projection display has an external light source producing as an output a light beam, an internal optics system, and a housing in which the internal optics system is received, but wherein the external light source is located external to the housing. A display screen forms one face of the housing. Preferably, an optical fiber extends from the output of the external light source to an input of the internal optics system. Multiple digital projection displays may be illuminated by a single external light source using multiple optical fibers.

Abstract: The thin-film optical filters and transmitted-light collimators of a multistage optical multiplexer/demultiplexer apparatus are assembled by locating the thin-film optical filters so that an incident light beam is incident upon and reflected sequentially from each thin-film optical filter to the next thin-film optical filter, and orienting each thin-film optical filter to produce a respective angle-of-incidence of the incident light beam on the thin-film optical filter so that a desired transmitted light beam is transmitted therethrough with a maximum intensity. The transmitted-light collimators are positioned to receive the respective transmitted light beams with minimal insertion loss. The respective steps of positioning are performed independently of, but after, the respective steps of orienting for each multiplexer/demultiplexer stage.

Abstract: A PIN detector device (190) is fabricated on a substrate (10). The substrate (10) includes a handle wafer portion (208), an implanted oxide layer (206), a backside contact layer (204) and an active wafer portion (202). The substrate (10) serves as a foundation to increase stability and facilitate handling during fabrication of electrical circuitry (248) on a surface of the active wafer portion (202). After the electrical circuitry fabrication processing is substantially complete, the handle wafer portion (208) and implanted oxide layer (206) are removed to expose the implanted backside contact layer (204).

Abstract: A window mounting system for optical sensors including a removable connection for window replacement, an alignment system to assure precision registration of the window or dome with the sensor internal optics, and thermal insulation to limit heat transfer from the window to the optics housing and sensor. The removable connection maintains precise optical alignment of curved domes with significant optical power, yet also is effective with simple flat windows.

Abstract: A wide-angle IR imaging system (1A) has an entrance aperture (40) for admitting IR from a scene and a dewar (4A) that contains a coldshield (3) that encloses a cooled IR detector (2) disposed at an image plane (2A). The dewar includes a dewar window (4), and an optical axis of the IR imaging system passes through the dewar window and the image plane. The IR imaging system further includes a plurality of uncooled optical elements (22, 24, 26, 28) disposed along the optical axis between the entrance aperture and the dewar window, and a plurality of generally annular reflector segments (18A, 18B) disposed around the optical axis between the dewar window and the entrance aperture. Each of the reflector segments has a reflective surface that faces the dewar window.

Abstract: A zoom lens assembly (10) compensates optically, as opposed to mechanically, for changes in temperature. In a preferred embodiment a difference in focus between WFOV and NFOV zoom lens positions, over temperature, is minimized such that any actual shift in focus falls within the depth of focus of the zoom lens assembly. The zoom lens assembly has, along an optical axis, first and third lens elements (12,16) that are made from a first material and that have a positive power, a second lens element (14) interposed between the first and third lens elements and movable along the optical axis between a WFOV and NFOV position. The second lens element has a negative power and is made of a second material. The materials are selected such that a change in refractive index for a change in temperature of the first material is less than a change in refractive index for a change in temperature of the second material.

Abstract: A digital projection display includes a light source producing a light beam, and an integrator, an illumination lens, an illumination fold mirror, a light director, and a digital light modulator which sequentially process the light beam. The digital projection display further has a projection lens that receives the spatially modulated light beam from the light director and includes two projection lens elements. A projection lens fold mirror is disposed between the two projection lens elements. A projection fold mirror receives the light beam from the projection lens and redirects the light beam to a display.

Abstract: A projection display includes a light source, a spatial light modulator that receives a light from the light source, and an angle-selective coating disposed to receive the light beam from the spatial light modulator. The angle-selective coating is oriented at a non-zero inclination angle to the light beam. The angle-selective coating has a higher transmission for light that is incident upon the angle-selective coating at an incidence angle within an acceptance-angle deviation from a design incidence angle, than for light that is incident upon the angle-selective coating at an incidence angle greater than the acceptance-angle deviation from the design incidence angle. The projection display preferably includes a TIR (total internal reflection) prism disposed to reflect a light beam from the light source to the spatial light modulator, and to receive the light beam from the spatial light modulator. The angle-selective coating is preferably buried within the TIR prism.