Dissertation Talk: Design and Fabrication of VCSELs for 3D Sensing

Presentation | November 8 | 3-4 p.m. | 540AB Cory Hall

 Kevin Cook

 Electrical Engineering and Computer Sciences (EECS)

The demand for low-cost laser sources for 3D imaging in industrial, medical, and consumer applications has created a rapidly growing market for vertical cavity surface emitting lasers (VCSELs). These devices can be configured as widely tunable laser sources using a MEMS actuated mirror, or into high density arrays for powerful, spatially structured light.

In the first half of this talk, I will present a design rule for wavelength tunable VCSELs that can increase the tuning range of the device without increasing the threshold current. By creating an antiresonant semiconductor cavity, the laser mode can be confined more strongly in the tunable air gap, which increases sensitivity to the position of the tuning mirror.

In the second half of this talk, I will present a new method for fabricating a high-contrast grating reflector that utilizes the selective oxidation of AlGaAs. This method reduces the thickness of the epitaxy by one quarter, which reduces cost and increases throughput. I will discuss my solutions to new challenges that are created in this trace between epitaxial complexity and fabrication complexity.