Trumpf Photonics, Inc.

Stefan Heinemann

Thilo Vethake

Prasanta Modak

Suhit Ranjan Das

Robert Wallace Roff

Yufeng Li

Jeffrey Eisenmann

Berthold Schmidt

Le Zhao

Carlo Holly

Hans-Georg Treusch

Methods, devices, and systems for laser diode packaging platforms are provided. In one aspect, a laser diode assembly includes a heat sink and a plurality of laser diode units horizontally spaced apart from one another on the heat sink. Each laser diode unit includes: a first submount positioned on the heat sink and spaced apart from adjacent another first submount, a laser diode including an active layer between a first-type doped semiconductor layer and a second-type doped semiconductor layer, a bottom side of the laser diode being positioned on the first submount, and a second submount positioned on a top side of the laser diode and spaced apart from adjacent another second submount. The first submount, the laser diode, and the second submount in the laser diode unit are vertically positioned on the heat sink. The laser diodes of the plurality of laser diode units are electrically connected in series.

Laser diode packaging platforms

Methods, devices, and systems for double-sided cooling of laser diodes are provided. In one aspect, a laser diode assembly includes a first heat sink, a plurality of submounts spaced apart from one another on the first heat sink, a plurality of laser diodes, and a second heat sink on top sides of the plurality of laser diodes. Each laser diode includes a corresponding active layer between a first-type doped semiconductor layer and a second-type doped semiconductor layer. A bottom side of each laser diode is positioned on a different corresponding submount of the plurality of submounts. The plurality of laser diode are electrically connected in series.

Double-sided cooling of laser diodes

A laser diode bar: includes a semiconductor substrate comprising a first semiconductor layer of a first conductivity type; a first laser diode stack on an upper side of the semiconductor layer; a second laser diode stack on the upper side of the semiconductor layer, the second laser diode stack being electrically connected in series with the first laser diode stack, in which an electrical conductivity of the first semiconductor layer of the first conductivity type is higher than an electrical conductivity of each semiconductor layer of the first and second laser diode stacks; and a first electrode layer on the first laser diode stack, in which the first electrode layer electrically connects the first laser diode stack to a portion of the first semiconductor layer of the first conductivity type that is between the first laser diode stack and the second laser diode stack.

Low current, high power laser diode bar

A laser diode device includes: a first heat sink including a first mounting layer, in which the first mounting layer includes at least two mounting pads electrically isolated from one another; a second heat sink including a second mounting layer, in which the second mounting layer includes at least two mounting pads electrically isolated from one another; and a laser diode bar between the first heat sink and the second heat sink, in which a bottom electrical contact of the laser diode bar is mounted to the first mounting layer, and a top electrical contact of the laser diode bar is mounted to the second mounting layer.

Double sided cooling of laser diode

A semiconductor laser diode includes multiple layers stacked along a first direction, in which the multiple layers include: a first multiple of semiconductor layers; an optical waveguide on the first multiple of semiconductor layers, in which the optical waveguide includes a semiconductor active region for generating laser light, and in which the optical waveguide defines a resonant cavity having an optical axis; and a second multiple of semiconductor layers on the optical waveguide region, in which a resistivity profile of at least one layer of the multiple layers varies gradually between a maximum resistivity and a minimum resistivity along a second direction extending orthogonal to the first direction, in which a distance between the maximum resistivity and the minimum resistivity is greater than at least about 2 microns.

Laterally tailoring current injection for laser diodes

A laser diode assembly contains a plurality of laser diode chips packaged closely in a row. Each laser diode chip is bonded on both P-side and N-side to first and second sub-mounts. The sub-mounts are then attached to a cooling carrier, with both bonding surfaces perpendicular to the top surface of the carrier. The direction of laser radiation is parallel to the carrier top surface, and the distance between the top of the active area of the laser diode chip and the carrier is preferably in a range of half a pitch between individual laser sources packaged in a row or preferably in a range of 0.2 mm to 1 mm to allow efficient cooling for high power operation. The sub-mounts may be electrically conductive, or they may be of insulating material at least partially covered with a conducting layer. A laser diode chip is bonded uniquely to a set of sub-mounts or may share a sub-mount with another laser diode chip.

Multi-emitter diode laser package

A laser module has a unitary base including stepped platforms with an offset relative to an adjacent platform, each stepped platform accommodating a laser source with at least a first and a second plurality of stepped platforms, each platform accommodating a cooling channel inside at a predetermined depth below the top surface of the platform to conduct a flow of cooling fluid provided on an inlet, the cooling channel running under a platform having microchannels, the cooling channels being connected to a fluid inlet with an inlet manifold that provides cooling fluid at the inlet and an outlet manifold to dispose the cooling fluid with waste heat at an outlet, the laser module producing in one embodiment no less than 100 Watt of optical power.

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Hightstown, NJ, United States of America

Stefan Heinemann