Dissertation Defense Announcement

Yigit Ozan Yilmaz, Optical Science and Engineering PhD Candidate

Dissertation Title:

"External wavelength stabilization of grating coupled surface emitting lasers and applications"
(Under the direction of Dr. Eric Johnson)

Abstract :

In this research, external wavelength stabilization of broad area grating coupled surface emitting lasers (GCSELs) by an external feedback grating are investigated. One-dimensional (1D) and two-dimensional (2D) external cavity GCSEL arrays were fabricated and tested. This dual grating external cavity surface emitting laser (DGECSEL) is combination of a GCSEL device and an external grating operating under Littrow condition. The gratings were fabricated on silicon wafers using projection lithography, which enabled the positioning of different period gratings on the silicon wafer to match with the GCSEL device spacing on the laser bar.

The monolithic approach for   wavelength stabilization of GCSELs with internal dual grating reflectors (DGR)  are also investigated for multi-wavelength 1-D vertical stack array fabrication.

Furthermore, blue light generation using GCSEL based devices were experimentally investigated. Single wavelength and multi-wavelength blue light generation efficacy is measured   using single  DGECSEL and GCSEL/ DGR devices as well as  1-D DGECSEL and 1-D vertically stacked GCSEL/DGR devices.