Abstract: A relative position sensor is suitable for inertial navigation situations in which deviations from a predetermined position schedule are detected. A standing wave is established between a pair of opposed phase conjugate reflectors in a resonating cavity, and relative movement between the standing wave and the cavity is sensed. Since the standing wave continues to travel at its initial velocity regardless of deviations from that velocity by the resonator, deviations in the position of the resonator relative to its projected position based on the initial velocity can be measured. In a preferred embodiment, four-wave mixers are used as the phase conjugate reflectors, the phase conjugate medium within the mixers is made coextensive with the wave propagation medium between the mixers, and relative movement is sensed by monitoring the intensity of the standing wave at at least one location which is fixed relative to the resonator.

Abstract: Disclosed is an apparatus for removing electromagnetic energy at a wavelength .lambda. from a beam of electromagnetic energy. Included is an electro-optically tunable Fabry-Perot filter, with an electro-optic crystal having parallel incident and exit surfaces, a first transparent electrode on the incident surface, a second transparent electrode on the exit surface, an incident reflecting layer, and an exit reflecting layer. A detector produces an electrical signal in response to the electromagnetic energy transmitted by the filter. A lock-in amplifier receives the electrical signal and outputs to a control amplifier which also receives as an input a source of alternating current. A high voltage amplifier receives the output of the control amplifier and applies its output across the electro-optic crystal.

Abstract: Infrared detector arrays have focal plan processing in modular form mounted on stacked boards, where the processing integrated circuits are recessed in adjacent boards.

Abstract: A multiple cavity electro-optic tunable filter includes an ordered row of n electro-optically tunable plates (n=2, 3, 4 . . . ), each plate having an incident surface and an emergent surface, an incident reflective coating on the incident surface of the first tunable plate in the row, an emergent reflective coating on the emergent surface of the nth tunable plate in the row, and a series of (n-1) absorbent films, one of the films being disposed between each pair of adjacent plates in the row in mating contact with the adjacent surfaces of the adjacent plates.

Abstract: Disclosed is an optical filter, including a plurality of adjacent layer pairs, each pair having an incident and an emergent surface and including a first dielectric layer having a thickness t and a refractive index n, a second dielectric layer, adjacent to the first layer, having a thickness t and a refractive index n, and a control electrode disposed between and in electrical contact with the layers. The filter further includes a plurality of ground electrodes disposed on the layer pairs to electrically contact each incident and emergent surface, a source of electric potential, and a switch for connecting the source between the control electrodes and the ground electrodes, whereby light having a wavelength .lambda.=4nt will be reflected by the filter upon closing the switch and thereby applying the electric potential in opposite directions across the first and second layer pairs. The plurality of layer pairs may include m layer pairs, with the thickness of each dielectric layer in the ith pair (i=1, 2, 3 . .

Abstract: A probe station having a cryogenic container preferably situated in a vacuum chamber. Semiconductor devices to be tested are attached to the container of cryogenic liquid. Electrical contact to the devices is made using contact wires which are moved by manipulators lying outside the vacuum chamber. Integrity of the vacuum at the manipulators is assured by using bellows to allow for the movement of the contact wires. Visual placement of the contact wires on the devices to be tested is accomplished with the aid of a microscope external to the vacuum. One end of the vacuum chamber is made of clear plastic to be used as the microscope viewing window. A spring is used external to the vacuum space to counteract the effects of atmospheric pressure on the movable bellows. The semiconductor devices are then tested by the connection of the appropriate test equipment to the electrical contact wires.

Abstract: A method of interconnecting microelectronic components with flexible metallic interconnects. A layer of photoresist is applied to the surface of a microelectronic component and then removed from selected locations. A deposit of metal is applied to the selected location. A second layer of photoresist is applied over the first layer and over the deposited metal. The second layer of photoresist is removed from above the metal deposit and a second metal deposit is applied over the first metal deposit. These steps are repeated until a predetermined height of deposited metal is reached supported by layers of photoresist. The upper surface of the deposit and photoresist is polished flat and pads of metal deposited. A second microelectronic component having mating metal pads is positioned over the first microelectronic component and bonded to it through the mating metal pads. Finally, the layers of photoresist are removed.