Sdl Inc.

James M Haden

Michael P Staskus

John G Endriz

Robert J Lang

Alexander Schoenfelder

The invention relates to laser diode arrays having high beam quality and high beam brightness. In one approach, a laser diode array package includes a mount and first and second laser diode arrays disposed on the mount. Each of the laser diode arrays defines an optical axis and has an emitting surface lying in an emitting surface plane. The emitting surface plane of the first laser diode array is displaced relative to the emitting surface plane of the second laser diode array in a direction parallel to one of the optical axes. The optical axes of the first and second laser diode arrays are offset from each other in a direction perpendicular to one of the optical axes. First and second lenses are disposed relative to respective emitting surfaces to reduce divergence of light output from the emitting surfaces. In another approach, laser diode array bars are stacked and the individual output beam from each bar is collimated using a short focal length, low aberration lens. The resulting collimated beams are treated with reflectors to reduce, or remove, the dead spaces between adjacent collimated beams, thus permitting the use of low aberration lenses, which results in an improved divergence-size product for each beam produced by a bar. Additionally, the total beam output by the array of laser bars is condensed in size.

Laser diode array assemblies with optimized brightness conservation

A high-power two-dimensional edge-emitting diode laser array comprises mounting modules, laser bars mounted on the modules, and protective caps mounted on the bars opposite the modules. The lasers are electrically connected in series through the modules and caps. The caps serve as laser bar protectors during the bar burn-in. The caps have grooves which compensate for tolerances in the thicknesses of the lasers, modules, and caps. The array is mounted on a base plate, and is in thermal communication with a heat sink. The caps and/or modules are thermal-expansion-matched to the laser bars. Eliminating the need for a wire bond plate allows shortening the modules.

No wire bond plate (NWBP) packaging architecture for two dimensional

A mounting module (submount) for a high-power heat-dissipating element comprises a mounting plate thermal-expansion-matched to the element, a high-thermal-conductivity bulk layer having stress-relief apertures, and an auxiliary plate bonded to the bulk layer opposite the mounting plate. The element is mounted on the mounting plate, while the bulk layer is attached to the mounting plate on the side opposite the element. The apertures accommodate the expansion of the bulk layer along a major dimension of the mounting plate. The apertures run transverse to the mounting plate, so as not to impede heat flow through the mounting plate. The apertures serve either as reservoirs for excess solder during module assembly, or as conduits for cooling fluid. The bulk layer comprises either stacked sheets having aperture sections defined prior to assembly, or blocks defining the apertures at the block interfaces. Suitable heat-dissipating elements include high-power, high-duty cycle diode lasers and laser arrays, FETs, MOPAs, thyristors, and other high-power electronic components. For a GaAs laser bar, the mounting plate can be a thin CuW or Cu/Mo plate, while the bulk layer may be made of Cu. The stress-relief allows brazing the bulk layer and the mounting plate.

Expansion-matched high-thermal-conductivity stress-relieved mounting

A cooler features a plurality of microchannels each of which includes a plurality of baffles disposed therein to avoid laminar flow within each microchannel through modulation which varies both the direction and velocity of fluid flowing through each microchannel. The microchannels are formed between a plurality of spaced apart thermally conductive fins, which are arranged to extend from a thermally conductive substrate adapted to be in physical contact with a region to be cooled. The fins are formed by stacking a plurality of thin sheets along a direction transverse to a longitudinal axis of the microchannels. Each sheet includes a plurality of apertures spaced apart along two transverse directions, both of which are transverse to the stacking direction. The baffles are formed from the spaces disposed between the apertures. Preferably, each sheet is formed from copper which is chemically etched to form the apertures in the sheet.

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San Jose, CA, United States of America

James M Haden