Opto Power Corporation

Swaminathan Thandalai Srinivasan

Rushikesh M Patel

Rajiv Agarwal

Xiaoquang He

Kenneth Joseph Thibault

Multi-layer, semiconductor devices are configured to reduce stress by the removal of much of the structure which does not actually contribute to device performance. In one embodiment, trough between mesas which define light emitting facets in a laser diode bar are etched well into the substrate to remove all layers of different compositions there. In another embodiment, troughs are also etched in the backside of the substrate of a laser diode structure where the troughs are aligned along axes perpendicular to the axes of the mesas. The removal of stress permits more accurate alignment of the multiple facets along a single axis when the laser bar is bonded to a heat sink. The accurate alignment minimizes the placement constraints on the position of a microlens for achieving maximum power output and coupling efficiency for optical fibers coupled to the microlens.

Multi-layer semiconductor devices with stress-relief profiles

Quantum well lasers are herein made with purposely-graded interfaces which control the interdiffusion of atoms during high temperature processing. The result is a predictably-graded, large interface between the quantum well and the waveguide layers to either side thereof. The process is highly controllable and produces unique structures which exhibit surprisingly high power in a repeatable manner.

Quantum well laser with a composition-graded interface at the quantum

A reduced, lateral mode laser diode is fabricated using a self-aligning process which produces a well controlled weakly index-guided waveguide with strong current confinement. The structure includes ion implants for controlling current injection into the active region from the top of the ridge. The number of modes may be reduced to unity, resulting in a single lateral mode laser. A laser diode array is fabricated in the same way.

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Tucson, AZ, United States of America

Swaminathan Thandalai Srinivasan