Abstract: A modulation process with a fully suppressed carrier and input preprocessor filtering to produce an encoded output; for amplitude modulation (AM) and audio speech preprocessor filtering, intelligible subjective sound is produced when the encoded signal is demodulated using the RF Hearing Effect. Suitable forms of carrier suppressed modulation include single sideband (SSB) and carrier suppressed amplitude modulation (CSAM), with both sidebands present.

Abstract: An optically pumped semiconductor laser with the active region partitioned such that different wavelengths can be emitted simultaneously from each partitioned region. The material of the partitioning layers is selected to be transparent to the pump wavelength, an electronic barrier to carrier diffusion, and epitaxially compatible with subsequent layers of the laser structure.

Abstract: A tool for removing ball grid array (BGA) packaged integrated circuit or multi-chip modules from printed circuit boards is comprised of a two-tined fork with a heated wire stretched between the tips of the tines and a thin sheet of material filling the area between the tines.

Abstract: A method for fabricating an optical quality, free-standing, compliant parabolic membrane mirror using an inverted parabolic mandrel created by rotating a liquid confined to a cylindrical polymer and applying a reflective optical stress coating once the substrate has hardened. The stress coating applies a tensile force to the substrate that offsets the stress in the substrate that would otherwise decrease the convexity, and also generates a force to restore the membrane mirror to its original convex parabolic shape when the mirror is deformed by an external force.

Abstract: An optical configuration and related analysis techniques are presented that provide a practical method for determining the Rytov parameter based on the difference of variances for the differential image motion (average wavefront gradient or wavefront tilt) between two receiving apertures. The Rytov parameter is the log-amplitude variance predicted by an approximate solution to Maxwell's equations for propagation through media with random index of refraction (Rytov theory). It is a useful metric of the optical effects for extended turbulence propagation and is a leading indicator of the performance limitations of adaptive optical compensation devices not related to the transverse coherence diameter. A time-duplex alternative apparatus and a single source alternative apparatus are also disclosed.

Abstract: PRS0847A foveated imaging system using a relatively simple optical imaging system with a reflective spatial light modulator at or near a pupil plane to correct off-axis aberrations. Maximum resolution is obtained for a single fixation point (foveal region) within the field of view at a time. The fixation point can be changed manually, by a predetermined scan pattern, or automatically varied for surveillance or tracking applications. A pre-calibrated look up table is used to vary the reflective spatial light modulator for each fixation point.

Abstract: A modulation process with a fully suppressed carrier and input preprocessor filtering to produce an encoded output; for amplitude modulation (AM) and audio speech preprocessor filtering, intelligible subjective sound is produced when the encoded signal is demodulated using the RF Hearing Effect. Suitable forms of carrier suppressed modulation include single sideband (SSB) and carrier suppressed amplitude modulation (CSAM), with both sidebands present.

Abstract: A composite capacitor/inductor assembly has been developed that merges the capacitance utilized for energy storage into the inductor, creating a consolidated electrical component. The composite capacitor/inductor is capable of functioning in those applications requiring resonant circuits for frequencies in excess of 100 MHz. The composite nature of the device reduces by one-half the number of components required to produce a resonant circuit.

Abstract: The head of an optical fiber comprising the sensing probe of an optical heterodyne sensing device includes a planar surface that intersects the perpendicular to axial centerline of the fiber at a polishing angle &thgr;. The planar surface is coated with a reflective material so that light traveling axially through the fiber is reflected transverse to the fiber's axial centerline, and is emitted laterally through the side of the fiber. Alternatively, the planar surface can be left uncoated. The polishing angle &thgr; must be no greater than 39° or must be at least 51°. The emitted light is reflected from adjacent biological tissue, collected by the head, and then processed to provide real-time images of the tissue. The method for forming the planar surface includes shearing the end of the optical fiber and applying the reflective material before removing the buffer that circumscribes the cladding and the core.

Abstract: An electronic circuit is described that adapts the output of a position-sensing detector, designed to determine the position of an incident CW laser beam, to determine the position of a fast pulsing laser incident on the detector's surface.

Abstract: An all gas phase iodine cw laser operating on the electronic I(2P3/2)−I*(2P1/2) transition of atomic iodine at 1.315 &mgr;m was described. The laser is based on the energy transfer reaction between metastable NCl(a1&Dgr;) and ground state I(2P3/2) atoms. This all gas phase laser has a number of advantages over previous aqueous-based chemical oxygen iodine lasers, including lighter weight, zero-gravity operation, and heat rejection in the exhaust.

Abstract: A free-space optical interconnect architecture is presented that is tolerant of the lateral misalignment of integrated circuit boards in multi-chip module packages. Each transmitter has a different wavelength and correspondingly sensitive detector. The transmitted beams are spread such that the beams' half angles are slightly greater than the maximum expected misalignment.

Abstract: A method for real-time, robust, stable closed-loop control of two phase correction devices to compensate for both amplitude and phase fluctuations induced by light passing through a turbulent medium. Two phase correction devices, in different conjugate planes, are controlled to minimize the difference in phase of the input beam corrupted by turbulence and an ideal reference beam.

Abstract: An AMTEC cell is improved by using a grooved wall of high specularity in the low-pressure zone. The cell's parasitic heat transfer is reduced by reflecting radiant energy back toward the high-temperature end of the cell and by increasing the wall heat conduction path. Efficiency is improved by both increasing the temperature of the BASE structure and by reducing the parasitic heat transfer. A heat shield of similar construction located within the low-temperature zone is also disclosed.

Abstract: A specially cut uncoated birefringent crystal having three Brewster-cut faces with adjacent coated Brewster-cut coupling prisms are used for optical frequency conversion. Two input frequencies are used to obtain a third frequency by sum-frequency generation. The uncoated birefringent crystal permits high power input beams.

Abstract: A foveated imaging system using a relatively simple optical imaging system with a spatial light modulator located at or near a pupil plane to correct aberrations. Maximum resolution is obtained for a limited region defined by a single fixation point (a foveal region) within the field of view. The fixation point can be changed manually, by using a predetermined scan pattern, or automatically varied for surveillance or tracking applications.

Abstract: A slotted coaxial shield for high voltage cylindrical air core transformers is described that controls the electric field stress while permitting the rapid extraction of electric energy stored in the shield to improve the output efficiency.

Abstract: A specially cut uncoated birefringent crystal having three Brewster-cut faces with adjacent coated Brewster-cut coupling prisms for optical frequency conversion. Two IR input frequencies are used to obtain a third visible light frequency by sum-frequency generation. The uncoated birefringent crystal permits high power input beams. The two Z-polarized IR beams enter the lower portion of the Brewster cut IR input end of the crystal and pass out the Brewster cut lower portion of the output end, generating a Y-polarized visible light beam. The visible wavelength beam is reflected at the Brewster cut Z-polarized surface at the output end and again reflected at the upper output end surface cut perpendicular to the Brewster cut. The visible beam travels back toward the IR input end near the top surface of the crystal and exits through an upper Brewster cut surface cut for Y-polarized light. Input and output prisms with appropriate optical coatings are used to facilitate the process.

Abstract: An inclinometer utilizing synchronous demodulation for high resolution and electronic offset adjustment provides a wide dynamic range without any moving components. A device encompassing a tiltmeter and accompanying electronic circuitry provides quasi-leveled tilt sensors that detect highly resolved tilt change without signal saturation.

Abstract: An apparatus and method is disclosed for reducing inductive coupling between levitation and drive coils within a magnetic levitation system. A pole array has a magnetic field. A levitation coil is positioned so that in response to motion of the magnetic field of the pole array a current is induced in the levitation coil. A first drive coil having a magnetic field coupled to drive the pole array also has a magnetic flux which induces a parasitic current in the levitation coil. A second drive coil having a magnetic field is positioned to attenuate the parasitic current in the levitation coil by canceling the magnetic flux of the first drive coil which induces the parasitic current.