United Technologies Corporation

Northrop Grumman Systems Corporation

William L Nighan

Frank K Tittel

Walter J Wiegand, Jr

Robert T Brown

William L Wilson, Jr

Carl M Ferrar

Russell A Budzilek

Fred A Otter, Jr

Roland A Sauerbrey

Fred A Otter

An electroluminescent display having reversible polarity and a method for reducing latent images in the electroluminescent panel is provided. The electroluminescent display includes a waveform generator for supplying voltage pulses to illuminate pixels within the electroluminescent panel. The electroluminescent display according to the invention periodically reverses the polarity of the voltage pulses to reduce latent images in the electroluminescent panel. The electroluminescent display preferably utilizes an asymmetrical drive scheme to provide a brighter electroluminescent display.

Electroluminescent display having reversible voltage polarity

A transverse electrically excited gas laser comprises a mixture of rare gases and a fluorine donor at selected partial pressures so as to permit UV and/or visible rare gas-halide laser oscillation at two or more wavelengths simultaneously.

Multiple wavelength excimer laser

An excimer optical display includes a plasma panel device having therein a mixture of gas comprising xenon and molecular fluorine and a selected amount of other gases forming XeF excimer molecules such that the color of fluorescence is adjustable over a broad spectrum by selection of the gas mixture constituents.

Optical display from XeF excimer fluorescence

An improved electric discharge XeF excimer laser employs a reaction gas mixture containing NF.sub.3 and F.sub.2 in proportions that tailor the kinetics of the electrochemical reactions in order to achieve a substantial increase in power.

Two-halogen donor mixture for XeF (C.fwdarw.A) laser

A xenon fluoride (C.fwdarw.A) laser operating in the visible region is improved by the use of a synthesized buffer gas containing at least two components that combine to provide kinetic properties that are different from those of any single-component buffer gas.

Multi-component buffer gas mixture for XeF(C.fwdarw.A) laser

A display device employs an electric discharge passing through a mixture of gases to form an excimer that fluoresces in the blue/green region of the optical spectrum.

Optical display with excimer fluorescence

The onset of electric discharge instability in rare-gas monofluoride lasers pumped by electron beam sustained electric discharges (e.g., KrF*) is delayed by employing a laser gas mixture (such as 0.95 Ar, 0.05 Kr, and 0.005 F.sub.2) which includes a small amount of a halogen compound (NF.sub.3) having a rate coefficient for electron dissociative attachment which is much larger than that for fluorine (such as 0.0005 NF.sub.3). The addition of nitrogen trifluoride to the gas mixture modifies the halogen kinetics in a manner to reduce the effect that consumption of the fluorine fuel has on the growth of secondary electrons, and therefore the occurrence of instability in the discharge. The rare-gas metastable quenching coefficient for the nitrogen trifluoride is sufficiently small (on the order of six times smaller than that of the fluorine) so that the small amount of nitrogen trifluoride utilized to stabilize the discharge exerts little or no influence on the other laser processes.

Stability enhanced rare-gas monofluoride lasers

The onset of electric discharge instability in electron beam enhanced electric discharge lasers employing halides, such as rare-gas monohalides (e.g., KrF*) and mercury vapor halide (e.g., HgBr*), is delayed by limiting the production of secondary electrons during laser pulse generation, to account for critical loss of halogen or halide fuel. Secondary electron production is controlled, in order to extend the pulse duration before the onset of discharge instability, by temporal tailoring of the primary electron concentration in the electric discharge region across the temporal expanse of possible laser action; the population of primary electrons can be temporally restrained by temporal decrease of the current density of the electron gun output, as a function, for instance, of gun driving voltage, or by temporal defocusing of the electron beam so as to provide reduced densities within the electric discharge region. Secondary electron production is also controlled by tailoring the production of rare-gas metastables. The production of metastables is controlled, in turn, by temporal tailoring of the electric field so as to provide a decreasing electric field to neutral particle density ratio across the temporal expanse of the laser pulse.

Stability enhanced halide lasers

Electric discharge method and apparatus for producing a relatively large volume, diffuse glow gas discharge plasma for laser, chemical synthesis and other applications at high power, high pressure and high volume levels and such that plasma properties are dominated by collision processes and wherein the operational parameters of the electric discharge are established to provide an average gas residence time T.sub.R in a continuous wave convective electric discharge and a discharge duration time T.sub.P in a pulsed electric discharge that is approximately equal to the plasma instability growth time T.sub.G = CP/JE where P is the pressure in Torr, JE is the electric power density in Watts/cm.sup.3 and C is a constant typically about 10.sup.-.sup.4 for self-sustained gas electric discharges and 10.sup.-.sup.3 for externally sustained gas electric discharges and wherein the convective electric discharge apparatus have a flow baffle system with a transverse foamed plastic baffle and a transverse turbulence generator plate for establishing an approximately isotopic and uniform turbulent flow pattern in the electric discharge region and such that T.sub.R and T.sub.G are representative of local values.

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Manchester, CT, United States of America

William L Nighan