Wisconsin Alumni Research Foundation

University of Illinois

Alfalight Inc.

Eric Warren Stiers

Luke J Mawst

Henry Guckel

Nelson Tansu

Thomas L Earles

Michael P Nesnidal

Manoj Kanskar

Troy J Goodnough

Steven Meassick

Darren M Hansen

A semiconductor laser diode comprises a p-n junction. The p-n junction comprises a substrate, an n-type semiconductor layer, a p-type semiconductor layer, and a quantum well. The quantum well is disposed between the n-type semiconductor layer and the p-type semiconductor layer. The substrate is formed from a first material system, the n-type semiconductor layer is formed from a second material system, the p-type semiconductor layer is formed from a third material system, and the quantum well is formed from a fourth material system. The second material system is different from the third material system. The second material system and the third material system are selected such that there is an increase in the rate of recombinations of the electrons from the n-type semiconductor layer and the holes from the p-type semiconductor layer in the quantum well. This results in a lower turn-on voltage for the semiconductor laser diode.

Semiconductor laser diode

As edge-emitting semiconductor laser incorporating a narrow waveguide design is disclosed. The narrow waveguide expands the lateral mode size, creates a large modal spot size, and insures higher-order modes are beyond cutoff. Separate current confinement allows the current injection region to match the mode size. The resulting device exhibits single-mode operation with a large spot-size to high output powers.

Narrow lateral waveguide laser

A positioning system adapted for use with micromechanical actuators provides feedback control of the position of the movable element of the actuator utilizing a low Q sensing coil. The effective inductance of the sensing coil changes with position of the movable element to change the frequency of oscillation of a variable oscillator. The output of the variable oscillator is compared in a phase detector to a reference oscillator signal. The phase detector provides a pulsed output having a pulse duty cycle related to the phase or frequency difference between the oscillator signals. The output of the phase detector is provided to a drive coil which applies a magnetic force to the movable element which balances the force of a spring. The movable element can be displaced to a new position by changing the frequency of the reference oscillator.

Position control system for use with micromechanical actuators

Growing community of inventors

Madison, WI, United States of America

Eric Warren Stiers