Ltv Aerospace & Defense Company

Other

University of Iowa Research Foundation

Loral Vought Systems Corporation

Mark E Koch

William E Case

Nicholas J Krasutsky

William C Stwalley

A new system for millimeter wave electronic imaging is described. This system utilizes a spatial light modulator in the focal plane of the collection optics. Each pixel of the modulator is driven by a specific high duty cycle modulation function provided by a modulation function generation circuit. Thus the throughput radiation at each pixel is uniquely labeled(encoded). A post modulation detector sums the signal from all the pixels. Subsequent to detection, the appropriate transform of the sum signal yields specific pixel throughput radiation intensity levels. Several configurations are described including one transmittance configuration and two reflectance configurations. Three specific millimeter wave transmittance embodiments and one reflectance embodiment are also described.

Electronic imaging by encoded image detection

Devices and methods are taught by this invention of populating excited energy levels with fundamental particles. When these populated excited energy levels are further pumped, a population inversion used in quantum electronic applications can result. Each of the various methods involve pumping on an excited energy level of an elemental physical system to cause, by the absorption of energy, the transition of fundamental particles from the excited energy level to a higher energy level. Part of the energy is used for transition of fundamental particles residing in neighboring elemental physical systems from the lowest energy to the excited energy level.

Population inversion by excited energy level absorption

This invention provides a method and apparatus for controlled crystal growth. The apparatus involves two tandemly aligned heat pipes separated by a conductive sleeve. The heat pipes establish two different isothermal temperature zones while the sleeve defines a gradient zone. A crystallization zone is located in this gradient zone. The method for controlled growth of a crystal involves lowering an ampoule through the gradient zone at an effective rate.

Apparatus comprising heat pipes for controlled crystal growth

A preferred embodiment of an excimer laser has a heat pipe oven adapted to raise sodium therein to a temperature of about 800 Kelvin and thereby vaporize the sodium at a pressure of no more than about 0.1 atmosphere, the heat pipe oven having substantially transparent ends. A ring cavity made up of a plurality of mirrors and an adjustable birefringent filter circulates violet light of a desired wavelength through the transparent ends of the heat pipe oven, and a pump laser introduces radiation into the heat pipe oven at an energy high enough to ionize sodium therein to form Na.sub.3.sup.+ ions and free electrons. The recombination of Na.sub.3.sup.+ ions and free electrons causes the ions to dissociate into free sodium atoms and excited Na.sub.2 molecules which, when stimulated by violet light of the desired wavelength, further dissociate into two free sodium atoms and emit additional violet light of the desired wavelength.

Excimer laser pumped by dissociative recombination

A method and apparatus for rapidly erasing and rebiasing a thermoptic thin film. A thermal insulating material (16) is disposed adjacent a thermoptic thin film (10). A layer of resistive material (14) is disposed between the insulating material and the thermoptic thin film and is connected to a current generator (18) which supplies a current to the layer dissipating heat into the thermoptic thin film and insulating layer. A thermal body (22), having high thermal conductivity and interfacing with the insulating layer the opposite boundary from the thermoptic thin film, contains a conduit through which a refrigerated liquid is flowed to establish a thermal gradient from the thermoptic thin film to the fluid. Sufficient current is supplied to the resistive layer to maintain the temperature of the thermoptic thin film at the bias temperature. A control circuit is provided for intermittently interrupting the current flow, causing heat to dissipate from the thermoptic thin film and the temperature to drop to a point below the hysteresis loop, whereby images written in the thermoptic thin film are erased. A sensor (28) may be provided adjacent the thermoptic thin film for generating a temperature signal corresponding to the temperature of the film. The signal is fed back to the control circuit. When the temperature of the film drops below 45.degree. C. and the film is erased, sufficient current is then furnished to the resistive layer to cause the temperature of the film to increase to the bias temperature.

Growing community of inventors

Farmers Branch, TX, United States of America

Mark E Koch