University of Illinois

Eden Park Illumination

United States of America As Represented by the Secretary of the Air Force

Cu Aerospace, LLC

USA As Represented by Secretary of the Navy

James Gary Eden

Sung-Jin Park

David Loren Carroll

Clark J Wagner

Cyrus M Herring

Andrey Mironov

Andrew W McCown

David B Geohegan

Rodney L Burton

Joseph T Verdeyen

Ju Gao

Jason D Readle

Mark J Kushner

Dennis P Greene

Kevin P Killeen

Sehyun Park

Charles Shin

Marwood N Ediger

A plasma lamp is provided that employs excitation transfer between two atomic or molecular species so as to preferentially produce light at a specific atomic or molecular emission wavelength. The lamp includes a lamp body. The lamp body includes a top portion, a middle portion having an internal hollow space filled with an energy-donor chemical gas and an energy-acceptor chemical element, and a bottom portion. The lamp body further includes an array of a plurality of cavities connected to the internal hollow space. The internal hollow space and the array of the plurality of cavities are spaced apart from outer surfaces of the lamp body. The plasma lamp is configured to excite the energy-donor chemical gas by an ignition of a low-temperature plasma within the internal hollow space and the array of the plurality of cavities to cause an excitation transfer from the excited energy-donor chemical gas to the energy-acceptor chemical element, thereby emitting radiation having a wavelength of about 194 nm when mercury (Hg) is the energy-acceptor chemical element and helium (He) serves as the donor. Other wavelengths in the ultraviolet (UV) and vacuum ultraviolet (VUV) spectral regions are generated when other donor and acceptor atoms or molecules are employed. These lamps are well-suited as optical drivers for atomic clocks (such as the 40.5 GHz Hg ion clock), photochemical processing of materials, disinfection of water, air, and surfaces, as well as other applications requiring UV or VUV light.

Ultraviolet and vacuum ultraviolet lamps driven by molecular-atomic, atomic-atomic, or atomic-molecular excitation transfer

A product having at least one plasma lamp that includes plates that are approximately parallel, with at least one array of microcavities formed in a surface of at least one plate. When desirable, the plates are separated a fixed distance by spacers with at least one spacer being placed near the plate's edge to form a hermetic seal therewith. A gas makes contact with the microcavity array. Electrodes capable of delivering a time-varying voltage are located such that the application of the time-varying voltage interacts with the gas to form a glow discharge plasma in the microcavities and the fixed volume between the plates. The glow discharge plasma efficiently and uniformly emits radiation that is predominantly in the UV/VUV spectral range with at least a portion of the radiation being emitted from the plasma lamp.

High-power ultraviolet (UV) and vacuum ultraviolet (VUV) lamps with micro-cavity plasma arrays

A plasma lamp includes plates that are approximately parallel, with at least one array of microcavities formed in a surface of at least one plate. When desirable, the plates are separated a fixed distance by spacers with at least one spacer being placed near the plate's edge to form a hermetic seal therewith. A gas makes contact with the microcavity array. Electrodes capable of delivering a time-varying voltage are located on the surface of each plate. At least one electrode is located on an exterior surface of at least one interior plate. Optionally, protective windows may be placed over the electrodes. The application of the time-varying voltage interacts with the gas to form a glow discharge plasma in the microcavities and the fixed volume between the plates (when present). The glow discharge plasma efficiently and uniformly emits UV/VUV radiation over the entire surface of the lamp.

A method for generating a hybrid reaction flows feedstock gas that is also a plasma medium through microchannels. Plasma is generated with the plasma medium via excitation with a time-varying voltage. UV or VUV emissions are generated at a wavelength selected to break a chemical bond in the feedstock gas. The UV or VUV emissions are directed into the microchannels to interact with the plasma medium and generate a reaction product from the plasma medium. A hybrid reactor device includes a microchannel plasma array having inlets and outlets for respectively flowing gas feedstock into and reaction product out of the microchannel plasma array. A UV or VUV emission lamp has its emissions directed into microchannels of the microchannel plasma array. Electrodes ignite plasma in the microchannels and stimulating the UV or VUV emission lamp to generate UV or VUV emissions. One common or plural phased time-varying voltage sources drive the plasma array and the UV or VUV emission lamp.

Hybrid photochemical/plasma reactor devices

It is disclosed herein a breakthrough concept for in-space propulsion for future Air Force, NASA and commercial systems. The invention combines the fields of micro-electrical-mechanical (MEMs) devices, optical physics, and nonequilibrium plasmadynamics to reduce dramatically the size of electric thrusters by 1-2 orders of magnitude, which when coupled with electrodeless operation and high thruster efficiency, will enable scalable, low-cost, long-life distributable propulsion for control of microsats, nanosats, and space structures. The concept is scalable from power levels of 1 W to tens of kilowatts with thrust efficiency exceeding 60%. Ultimate specific impulse would be 500 seconds with helium, with lower values for heavier gases.

Micro-cavity discharge thruster (MCDT)

The present invention provides in one of the embodiments for either a continuous wave (cw) or pulsed alkali laser having an optical cavity resonant at a wavelength defined by an atomic transition, a van der Waals complex within the optical cavity, the van der Waals complex is formed from an alkali vapor joined with a polarizable gas, and a pump laser for optically pumping the van der Waals complex outside of the Lorentzian spectral wings wherein the van der Waals complex is excited to form an exciplex that dissociates forming an excited alkali vapor, generating laser emission output at the wavelength of the lasing transition.

Atomic lasers with exciplex assisted absorption

Start-up and re-ignition of a high pressure arc lamp are aided by injection of electrons toward a high pressure arc lamp electrode. A microdischarge device directs electrons toward an electrode of the arc lamp and is preferably turned off during normal operation of the arc lamp. The harsh environment of an arc lamp requires the microdischarge to be made from robust materials, such as ceramics, semiconductors or tungsten, for example. In the present invention, the discharge design must allow, preferably through a screen anode, for the escape of electrons from the microdischarge. This invention results in a decrease in the voltage required to start-up or re-ignite a lamp.

High pressure arc lamp assisted start up device and method

A miniature solid state laser is optically pumped by ultraviolet radiation produced by a surface or corona discharge. The device is monolithic in that both the optical pump and the active medium are contiguous to a base material which is optically transparent in the ultraviolet range. The disclosed device consists of a substrate, a thin metal halide or crystalline or amorphous film deposited on the bottom of the substrate and a pair of spaced electrodes on the top of the substrate. When a high voltage pulse is applied across the spaced electrodes, discharge occurs between the electrodes and produces strong ultraviolet emissions which propagate through the substrate and dissociates the metal halide molecules in the film. This causes laser emission to occur on an atomic transition of the metal atom. The active laser medium may also be a crystalline platelet or amorphous thin film containing an impurity atom or molecule (an example would be YAG doped with Nd or LiYF.sub.4 (YLF) doped with cerium). In this case, the active medium may provide its own mechanical support, provides a surface on which the discharge may occur and thus eliminates the need for a separate optical substrate.

Miniature, optically pumped narrow line solid state laser

A novel method and system for depositing films of selected metallic or semiconductor materials, and particularly of the group III, IV, and V elements, is described which comprises heating a halide compound of the material to produce vapor within a substantially closed chamber, irradiating the vapor with light of preselected wavelength to dissociatively photoionize the vapor into the constituent positive ions of the material and negative halogen ions, and subjecting the photoionized vapor to an electric field to selectively remove the positive ions of the material for plating as a film.

Photoionization technique for growth of metallic films

Unusual power enhancement and a plurality of output wavelengths in the visible or near-infrared regions are obtained simultaneously from a laser in which the vapors of two or more Group II-B metal halides are dissociatively excited either in an electrical discharge or by photodissociation by an external laser. By using halides involving only one metal and/or halogen isotope, the power output is greater than that obtainable with natural abundance salts. The laser output is also more confined spectrally. Over 50% of the power is contained in one or two spectrally narrow lines that are associated with a particular metal halide molecule.

Multi-wavelength metal halide lasers

The efficiency of pulsed laser systems is enhanced substantially by injecting a minor amount of radiation energy into the system .DELTA.t seconds prior to the emergence of the laser pulse. The degree of power enhancement is a function of both radiation wavelength and time delay.

Enhanced laser power output

Visible and ultraviolet lasers is based on excimer transitions in the diatomic homonuclear halogen molecules. Electron beam pumping of argon and hydrogen iodide gas mixtures produces a strong green emission in I.sub.2 centered at 505 nm and a full width of half maximum (FWHM) of the gain spectrum of approximately 15 nm. The transition for the green I.sub.2 band is bound-to-free, so a laser on this transition is continuously tunable. The result is a room temperature excimer laser that is potentially tunable over a region of 150 .ANG. in the blue-green.

Growing community of inventors

Champaign, IL, United States of America

James Gary Eden