Study of Cobalt-doped Cadmium Telluride for Solid-State Laser Applications

Date of Award

2018

Degree Name

M.S. in Electro-Optics

Department

Department of Electro-Optics

Advisor/Chair

Advisor: Jonathan Evans

Second Advisor

Advisor: Gary Cook

Abstract

Cobalt-doped cadmium telluride (Co:CdTe) has been studied to identify its spectroscopic features and potential as a solid-state laser gain medium. Within the class of transition-metal-doped chalcogenide solid-state gain media, iron-doped zinc selenide (Fe:ZnSe) and chromium-doped zinc selenide (Cr:ZnSe) have emerged as practical sources of tunable mid-infrared radiation. Meanwhile, cobalt remains comparatively unexplored. Co:CdTe has an emission band within the 3 - 5 ╡m atmospheric transmission window and potential to fill the 3 - 3.8 ╡m spectral gap between Cr:ZnSe and Fe:ZnSe. A spectroscopic investigation of Co:CdTe was performed, and the temperature dependent emission and absorption properties were collected from 10 - 120 K. Cross-sections were calculated using the Fuchtbauer-Ladenburg and reciprocity methods. The optical amplification of a 3.8 ╡m Intraband Cascade Laser (ICL) was demonstrated by pumping Co:CdTe with a 2.8 ╡m continuous-wave Er-fiber laser. This is believed to be the first successful gain demonstration of a cobalt-doped chalcogenide material. A laser rate equation model was implemented to predict the optical gain and a thermal model was developed to analyze the temperature rise of Co:CdTe under continuous-wave pumping conditions. The primary aim of this work is to study the optical transitions between the ground state and first energy level of the crystal field, as well as evaluate the potential of Co:CdTe as a mid-infrared gain medium.

Keywords

Engineering, Optics, Cobalt, Transistion-Metal-Doped Chalcogenide, Mid-Infrared Laser Amplifier, Solid-State Laser Amplifier, Laser Materials, Optical Spectroscopy

Rights Statement

Copyright © 2018, author

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