Northrop Grumman Systems Corporation

Northrop Grumman Space & Missions Systems Corp.

Trw Limited

Cutting Edge Optronics, Inc.

Northrop Grumman Space & Missions

Edward Franklin Stephens, Iv

Joseph L Levy

Jeremy Scott Junghans

John S Whiteley

Andrew M Singleton

Wade E Collins

Steven Michael Coleman

Michael L Fisher

Kevin L Callan

Francis L Struemph

Ryan M Crittenden

Courtney Ryan Feeler

Dean W Micke

Alan D Boxell

Frank L Struemph

An ammunition cartridge including a case, an ignitable material within the case and an optical primer for igniting the ignitable material. The optical primer includes a conductive cylindrical cup electrically coupled to the case and a circular conductive button including a top button portion positioned in the cup and a bottom button portion extending through an opening in the cup, where the button and the cup are electrically isolated. The optical primer further includes a first bracket electrically coupled to the button, a second bracket electrically coupled to the cup, and a pair of laser diodes electrically coupled in a reverse parallel direction and being electrically coupled to the first and second brackets, where one of the laser diodes generates a laser beam that ignites the ignition material in response to a current flow in either direction through the case, the cup and the button.

Ammunition cartridge including an optical primer

An optical primer for igniting an ignition material in an ammunition cartridge. The primer includes a conductive cylindrical cup electrically coupled to a cartridge case and a circular conductive button including a top button portion positioned in the cup and a bottom button portion extending through an opening in the cup, where the button and the cup are electrically isolated. The primer further includes a first bracket electrically coupled to the button, a second bracket electrically coupled to the cup, and a pair of laser diodes electrically coupled in a reverse parallel direction and being electrically coupled to the first and second brackets, where one of the laser diodes generate a laser beam that ignites the ignition material in response to a current flow in either direction through the case, the cup and the button.

Voltage polarity immunity using reverse parallel laser diodes

A laser system that allows transverse arrangement of laser emitters around a laser medium. The system includes a laser medium with a coolant source and electrical controls. A pump layer has a mounting surface, an opposite bottom surface and a center aperture through which the laser medium is inserted. Laser diode emitters are disposed on the mounting surface circumferentially around the laser medium. An intermediate layer has at least one radial channel in fluid communication with the coolant conduit. The intermediate layer is in contact with the bottom surface. A middle layer has micro-channels formed therethrough and a center aperture. The micro-channels are radially arranged around the center aperture and the middle layer is in contact with the intermediate layer. The coolant source is fluidly coupled to the micro-channels to allow coolant to be directed through the microchannels and the radial channel to impinge on the bottom surface.

Microchannel cooler for a single laser diode emitter based system

A method of fabricating a high-density laser diode stack is disclosed. The laser diode bars each have an emitter surface and opposing surfaces on either side of the emitter surface. Each laser diode bar has metallization layers on the opposing surfaces and a solder layer on at least one of the metallization layers. The solder layer is applied to a semiconductor wafer prior to cleaving the wafer to create the laser diode bars. The laser diode bars are arranged in a stack such that the emitter surfaces of the bars are facing the same direction. The stack of laser diode bars is placed in a vacuum chamber. An anti-reflection coating is deposited on the emitter surfaces of the laser diode bars in the chamber. The laser diode bars are joined by applying a temperature sufficient to reflow the solder layers in the chamber.

Methods of fabrication of high-density laser diode stacks

A laser diode package includes a laser diode, a cooler, and control circuitry, such as an integrated circuit. The laser diode is used for converting electrical energy to optical energy. The cooler receives and routes a coolant from a cooling source via internal channels. The cooler includes a plurality of ceramic sheets. The ceramic sheets are fused together. The ceramic sheets include traces or vias that provide electrically conductive paths to the integrated circuit. The control circuitry controls the output of the laser diode, e.g. the output at each of the laser diode's emitters. Multiple laser diode packages are placed together to form an array.

Laser diode ceramic cooler having circuitry for control and feedback of laser diode performance

A laser diode package includes a laser diode, a cooler, and a metallization layer. The laser diode is used for converting electrical energy to optical energy. The cooler receives and routes a coolant from a cooling source via internal channels. The cooler includes a plurality of ceramic sheets and a highly thermally-conductive sheet. The ceramic sheets are fused together and the thermally-conductive sheet is attached to a top ceramic sheet of the plurality of ceramic sheets. The metallization layer has at least a portion on the thermally-conductive sheet. The portion is electrically coupled to the laser diode for conducting the electrical energy to the laser diode.

Microchannel cooler for high efficiency laser diode heat extraction

A laser diode package () according to the present invention is tolerant of short-circuit and open-circuit failures. The laser diode package () includes a laser diode bar (), a forward-biased diode (), a heat sink (), and a lid () which may have fusible links (). The laser diode bar () and the forward-biased diode () are electrically connected in parallel between the heat sink () and the lid (). The emitting region of the laser diode bar () is aligned to emit radiation away from the forward-biased diode (). Several packages can be stacked together to form a laser diode array (). The forward-biased diode () allows current to pass through it when an open-circuit failure has occurred in the corresponding laser diode bar (), thus preventing an open-circuit failure from completely disabling the array (). The fusible links (), if used on the lid (), prevent damaged active regions () in a laser diode bar () from short-circuiting and drawing more electrical current than the other active regions ().

Fault tolerant laser diode package

A laser diode package according to the present invention is composed of CTE mismatched components soldered together. The laser diode package includes a laser diode bar, at least one heat sink, and at least one exothermic layer. Solder layers are adjacent the heat sink(s) and laser diode bar, respectively. The exothermic layer(s) are positioned between the solder layers. The exothermic layer(s) are exposed to an energy source which causes an exothermic reaction to propagate through the exothermic layer thereby melting the solder layers and solder layers. The exothermic layer(s) may be designed to provide sufficient heat to melt the solder layers and solder layers but provide only minimal heat to the laser diode bar and heat sink(s). Several packages can be stacked together to form a laser diode array.

Method of manufacturing laser diode packages and arrays

A laser diode assembly has a laser diode. The laser diode has an emitting surface and a reflective surface opposing the emitting surface. The laser diode has first and second side surfaces between the emitting and reflective surfaces. A first electrically-insulating heat sink is attached to the first side surface of the laser diode via a first solder bond, and the first heat sink has a first cooling channel. A second electrically-insulating heat sink is attached to the second side surface of the laser diode via a second solder bond, and the second electrically-insulating heat sink has a second cooling channel. A substrate has a top side and a bottom side, and the top side being in communication with a first bottom side of the first electrically-insulating heat sink and a second bottom side of the second electrically-insulating heat sink. The substrate has a flow channel system for passing a coolant to the first cooling channel and the second cooling channel. A metallization layer is attached to the first electrically-insulating heat sink and the second electrically-insulating heat sink. The metallization layer is electrically coupled to the laser diode and conducts electrical current to the laser diode. The metallization layer is isolated from the coolant.

Laser diode package with an internal fluid cooling channel

A laser diode package ( ) according to the present invention is tolerant of short-circuit and open-circuit failures. The laser diode package ( ) includes a laser diode bar ( ), a forward-biased diode ( ), a heat sink ( ), and a lid ( ) which may have fusible links ( ). The laser diode bar ( ) and the forward-biased diode ( ) are electrically connected in parallel between the heat sink ( ) and the lid ( ). The emitting region of the laser diode bar ( ) is aligned to emit radiation away from the forward-biased diode ( ). Several packages can be stacked together to form a laser diode array ( ). The forward-biased diode ( ) allows current to pass through it when an open-circuit failure has occurred in the corresponding laser diode bar ( ), thus preventing an open-circuit failure from completely disabling the array ( ). The fusible links ( ), if used on the lid ( ), prevent damaged active regions ( ) in a laser diode bar ( ) from short-circuiting and drawing more electrical current than the other active regions ( ).

A laser diode assembly includes a laser diode having an emitting surface and a reflective surface opposing the emitting surface. Between the emitting and reflective surfaces, the laser diode has first and second surfaces to which a first heat sink and second heat sink are attached, respectively, via a solder bond. A spacer element is disposed between the first and second heat sinks and is below the laser diode. The spacer element has a width that is chosen to provide optimum spacing between the first and second heat sinks. The spacer element has a height that is chosen to place the emitting surface of the laser diodes at a position that is substantially flush with the upper surfaces of the heat sinks. A substrate is positioned below the first and second heat sinks and is attached to these two components usually via a solder bond. The substrate is preferably of a nonconductive material so that electrical current flows only through the heat sinks and the laser diode. To properly locate the spacer element, the substrate may include a locating channel into which the spacer element fits. Each of the heat sinks is coated with a solder layer prior to assembly. Once the components are placed in their basic assembly position, only one heating step is needed to cause the solder layer on the heat sinks to reflow and attach each heat sink to the adjacent laser diodes and also to the substrate.

Growing community of inventors

Golden Eagle, IL, United States of America

Edward Franklin Stephens, Iv