Date of Award

12-2002

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Engineering Physics

First Advisor

Kenneth Schepler, PhD

Second Advisor

Won B. Roh, PhD

Abstract

Tunable lasers in the 2-4 µm wavelength range are needed for Air Force sensor applications. Chromium-doped II-VI materials are a promising class of laser material for tunable operation in this wavelength range, but until recently had not produced enough output power to meet application requirements. This dissertation investigates Cr2+:II-VI material properties and potential laser designs, then experimentally demonstrates and analyzes the performance of a Cr2+:ZnSe disk laser design that can produce sufficient output power. Cr2+:II-VI laser materials are found to be susceptible to overheating and thermal lensing, but are otherwise satisfactory laser materials. The most feasible laser design given a 15 W pump power limit was a face-cooled disk laser design using Cr2+:ZnSe. The experimental implementation of the laser design produced 4.3 W. However, the experimental laser worked well only under a restricted set of conditions, due to thermal lensing caused by a radially non-uniform absorbed power distribution in the laser disk. Design modifications are discussed which should reduce thermal lensing to acceptable levels. The conclusion is that Cr2+:II-VI laser sources can produce enough power for Air Force sensor applications, if enough effort is spent on ensuring adequate thermal management in the laser material.

AFIT Designator

AFIT-DS-ENP-02-05

DTIC Accession Number

ADA408929

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