STANTON, BRANDON MATTHEW. Characterization of Vertical Cavity Surface Emitting Lasers with Electrical and Optical Derivative Spectroscopy. (Under the direction of Robert Kolbas.)
The motivation behind this work is to use derivative spectroscopy to better understand the inner workings of Vertical Cavity Surface Emitting Lasers (VCSELs) provided by Honeywell Inc. Derivative spectroscopy was used to investigate two types of Honeywell VCSELs, Oxide confined VCSELs and Proton bombarded VCSELs. To quantify the devices I-V (current-voltage) and P-I (power-current) electrical and optical measurements were used to show the devices have no major problems and that the measurements are reproducible.
The I-V and P-I curves were taken to initially characterize devices. Having these curves supplies basic information such as laser threshold and data points for the slope of the operating regime. Using a voltage modulation technique derivative measurements dI/dV, d2IdV2, dL/dV were obtained and revealed subtle nonlinearities in the I-V and P-V data. Near field images of the optical output was correlated with the electrical measurements, and three mechanisms were identified that could be the cause of the derivative structure of the I-V curves.
