Northrop Corporation

Vahram W Biricik

Laurence S Gresko

Kang R Chun

John W Tully

James M Rowe

Paul Kraatz

Rudolph W Modster

Wesley J Thompson

John S Barnett

A semiconductor window which is transparent to light in the infrared range and which has good electrical conductivity is formed with a substrate of semi-conductor material which has a conduction modifying dopant diffused, grown or deposited on one surface thereof to a substantial depth so that a layer thereof exhibits reduced resistance to a value below 10 ohms/square. Anti-reflection dielectric layers are stacked on both outer surfaces thereof. The dielectric substrate may be of silicon, germanium or gallium arsenide depending on the transparency bandwidth of interest. The thickness of the substrate and the doping of the surface thereof is closely controlled to obtain both low electrical resistivity and high optical transmissivity.

Optically transparent electrically conductive semiconductor windows and

A cathode structure for a high power laser is formed from a first sheet of a hard metallic material such as molybdenum, which is joined to a second sheet of the same material by brazing, these first two sheets being brazed to a support structure of the same material. The first two sheets have a plurality of side by side longitudinal channels formed therein, the channels of one of these sheets being positioned between the channels of the other sheet (in a 180.degree. spatial phase relationship therewith). Crosswise channels are provided along opposite edges of both of the sheets to provide fluid communications to the opposite ends of the longitudinal channels. A cooling liquid such as water is fed to the transverse channels, and circulated through the longitudinal channels in parallel to effect efficient cooling of the cathode. The cathode is assembled by placing a thin foil of brazing material, such as a suitable gold/copper/nickel alloy, between the two channeled sheets and between one of the sheets and the support plate. Thin wires of hard material such as molybdenum are tack welded to the foil surfaces facing the channeled sheets, these wires running parallel to each other and normal to the direction of the channels. This structure is then placed in an airtight compartment and pressed between die surfaces. The compartment is then evacuated and the dies heated such as by electrical resistance to melt the brazing material and braze the cathode parts together to form an integral unit.

Cathode structure for a high power laser

An anode for an electron beam laser is formed by a thin metallic foil which functions both as a laser cavity wall having an airtight seal, and as a window which permits the passage of electrons therethrough into the laser cavity. This foil anode is supported on a frame structure in a manner such that the foil presents a smooth surface for the laser gas flow and the frame structure provides cooling for the anode to dissipate the heat generated by the electron flow. This frame structure includes a plurality of similar side-by-side, longitudinal, substantially flat, web elements which are separated from each other by gaps through which the electrons can pass. The web elements have cooling tubes welded to each of the opposite edges thereof, one of the tubes being capped with a flat strip which provides a flat surface against which the foil anode can be supported. The web elements are supported at their opposite ends by support blocks which are used to mount these elements in position between the electron gun and the laser cavity, with manifolds being provided in each of the support blocks for feeding cooling fluid to the tubes. The web elements are structurally supported and separated from each other by comb members which extend thereacross between the end blocks. A method is also described for assembling the anode support structure wherein plugs of brazing material are inserted in apertures formed in the web to braze the tubes to the end box and curved sheaths of brazing material are inserted between the tubes, the web and the cap to enable electrical brazing of the parts in a single step.

Anode assembly for high power electron beam laser

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Rancho Palos Verdes, CA, United States of America

Vahram W Biricik