Abstract: An all-reflective three-mirror afocal system has a negative power primary (12), positive power secondary (14), and positive power tertiary (16) mirror which form an afocal reimaging optical system. The system is capable of imaging very wide fields of view at low magnification and may be utilized in pilotage, navigation, driving or the like operations.

Abstract: A laser radar detection system (10) is provided for detecting targets located within a detection field and discriminating between unresolved and resolved detected objects (32,34). The detection system (10) employs a laser radar sensor (12) for transmitting a frequency modulated optical transmit signal (22) which scans a desires field and receiving a return signal (24) from objects located therein. The laser radar sensor (12) includes a photo mixer (20) for providing the difference between the return signal (24) and a local oscillator (LO) signal (26) derived from the transmit signal (22). A processor (14) is employed for receiving the difference signal and provides a fourier transform thereof to thereby provide a power spectrum in the frequency domain. The processor (14) analyzes the power spectrum to determine whether the transformed signal contains side lobes (40) and is therefore clutter or does not contain side lobes (40) and therefore indicates the detection of an unresolved object (32).

Abstract: In a Raman cell (10) which is subject to optical distortion of the path of a laser beam (40) by heating of the gas from the Raman conversion process, vibrating blades (50) cause the gas to mix and thus provide thermal homogeneity within the beam path.

Abstract: In one embodiment, a three-element biocular eyepiece system 40 having a first optical element 42 with at least one diffractive surface 44, a second optical element 48 having a refracting convex surface 50 and a refracting concave surface b 52 is provided. A third optical element 54 having a refracting convex surface 56 and a refracting convex surface 58 is also employed. In another embodiment, a four-element biocular system 60 is disclosed as having an optical element 62 having a refracting concave surface 64 and a refracting convex surface 66, a refractive-diffractive hybrid optical element 68 having a diffractive surface 70 and a refracting convex surface 72, an optical element 74 having a refracting convex surface 76 and a refracting concave surface 78, and an optical element 80 having a refracting concave surface 82 and a refracting convex surface 84. The diffractive surfaces 44 and 70 have a kinoform profile 102 a-d or approximated kinoform profiles 112a-d and 122a-d.

Abstract: A phase-locked-loop frequency synthesizer (18) normally applies a radio frequency (RF) drive signal (DRIVE) to a CO.sub.2 waveguide laser (10) at a first frequency which is optimal for continuous laser operation. For lighting the laser (10), a voltage-controlled oscillator (26) of the synthesizer (18) is forced to sweep the frequency of the drive signal (DRIVE) downwardly from a second frequency which is higher than the first frequency, through an intermediate third frequency which is optimal for laser lighting, to the first frequency. The laser (10) is lit during the downward sweep through the third frequency, and thereafter maintained at the first frequency for continuous operation.

Abstract: A semiconductor-to-metal optical switch or device for power limitation in the infrared spectral region includes two thin semiconductor layers sandwiched between two transparent electrodes. An electrical voltage is applied across the two semiconductor layers to produce an active device for blocking incident light in the 8 to 12 .mu.m spectral region. The material composition and thickness of the two semiconductor layers are such that enough photo-excited electrons are generated in the first semiconductor layer so that the second semiconductor layer undergoes a rapid semiconductor-to-metal transition at a predetermined light intensity. The semiconductor layers remain transparent below the predetermined light intensity and the second layer will become metal-like at a light intensity above a threshold level. Upon becoming metal-like, the second semiconductor layer will block the incident light.

Abstract: The present optical system provides an all-reflective afocal reimaging system. A reflective system receives, by means of an entrance aperture, and reflects radiation or light through the system such that the radiation or light is imaged and recollimated as it is reflected through the system. The radiation or light exits at an exit aperture which is an image of the entrance aperture. High quality images of both the collimated scene and reimaged aperture are formed by the optical system. Embodiments are shown by which the optical system can be used as an optical derotation device by the inclusion of two planar mirrors located near the entrance and exit apertures.

Abstract: A wide band large dynamic range current sensor operable to measure current leakage in an external conductor utilizing a magnetostatic spin wave delay line (MSW) device is described. The measurable changes in well known electromagnetic properties of ferrite films, as utilized in MSW devices when these films are exposed to external current induced magnetic fields, results in a current sensitive detection device. A method of current detection using this device is also described. Specific, low power microelectronic applications as well as, high power, local and remote current detecting embodiments are included.

Abstract: A radio frequency transmitting shutter operable at low power and high speed for use in the protection of a radar or electronic warfare array comprising a multiplicity of individual conductive beam members interconnected by electrostatic switches formed using high yield, common photolithographic methods is disclosed. Further, a photosensitive embodiment of this device which would allow activation of the shutter wherever the light falls upon the shutter during radar protection, is disclosed and claimed.

Abstract: A phased array radar antenna utilizing signal time delay magnetostatic spin wave devices operable to provide feed line transmit time control for variable length transmission feed lines. The preferred embodiment of an improved phased array radar antenna incorporates ferrite devices controlled by d.c. voltage driven ferroelectrics.

Abstract: A radar antenna utilizes groups of high frequency patch radiating element which are configured to function at two frequencies. The groups of patch radiators are configured to have a wide bandwidth and to make efficient use of the aperture while maintaining a thin cross-section.

Abstract: An improved phased-array active antenna transmit-receive means utilizing a multiplicity of individual transmit-receive cells positioned in an array format upon a common wafer of semiconductor material. Each transmit-receive cell, comprises a multiplicity of redundant, integrated circuit, electronic devices implanted upon the common semiconductor substrate. The transmit-receive cells utilize novel mitered mechanical switches to permanently interconnect individual electronic devices into either transmit or receive circuits during the fabrication and test of the transmit-receive cells. Radio frequency and direct current input and output vias formed from a novel metal evaporation technique connect the devices upon the surface of the common semiconductor wafer to underlying, insulated direct current distribution circuits and a radio frequency manifold.

Abstract: A multi-shell mated connector operable to provide electromagnetic interference (EMI), shielding protection for electrical circuits. This improved connector having at least one EMI seal may also incorporate a separate and additional EMI seal to function as an environmental seal to protect the connector pins from the outside environment. The preferred embodiment of this device is most suited for use in D style connectors which previously lacked effective EMI shielding between distinct, but mated connectors.

Abstract: A thermal heat transfer member is disclosed for use in electronic or microwave systems with particular application to advanced avionic systems. This thermal heat transfer member for line replaceable module (LRM) comprises; a bottom cover, a grid partition bottom means, a solid thermal plane material fixedly interconnected to the grid partition bottom means, a grid partition top means fixedly interconnected upon the thermal plane, sandwiching the thermal plane between the grid partition top and the grid partition bottom, and finally, a top cover. The utilization of a "building block" approach and composite high strength heat-conductive materials designed to dissipate heat away from electronic devices and components mounted within the LRM operate to produce a radio frequency LRM of high heat conductivity with reduced weight ideal for utilization in advanced development avionic systems subject to extreme G-force and stress in avionic system operation.

Abstract: An improved phased-array active antenna transmit-receive means utilizing a multiplicity of individual transmit-receive cells positioned in an array format upon a common wafer of semiconductor material. Each transmit-receive cell, comprises a multiplicity of redundant, integrated circuit, electronic devices implanted upon the common semiconductor substrate. The transmit-receive cells utilize novel mitered mechanical switches to permanently interconnect individual electronic devices into either transmit or receive circuits during the fabrication and test of the transmit-receive cells. Radio frequency and direct current input and output vias formed from a novel metal evaportion technique connect the devices upon the surface of the common semiconductor wafer to underlying, insulated direct current distribution circuits and a radio frequency manifold.