REU Project 10

REU Project 10

Studies of New Laser Materials
(Faculty Mentor - Dr. Sergey B. Mirov)

In this project, undergraduate students will be exposed to search and study of the new II-IV, I-III-VI2 and II-III-VI2 Cr2+ doped laser materials holding potential for lasing in the 2-5 mm Spectral Range. There is a growing demand for mid-infrared sources for use in a variety of applications including atmospheric sensing (global wind sensing and low altitude wind shear detection), eye-safe medical laser sources for non-invasive medical diagnostics, eye-safe laser radar and remote sensing of atmospheric constituents, optical communication, and for numerous military applications such as target designation, obstacle avoidance and infrared counter measures. These applications rely on existence of "spectroscopic fingerprints" of numerous organic molecules in the mid-IR. Recent research advances have spurred considerable effort in the development of practical mid-IR sources. In contrast to the large body of work using the difference frequency generators and mid-IR semiconductor diode lasers, there has been little investigation on potential for direct emission from chromium-doped crystals in this wavelength region. Recently, mid-IR lasers tunable over 2.1-2.8mm region were reported for Cr:ZnS and Cr:ZnSe crystals.

We have identified the following three projects for REU Students:

· REU student will study and optimize rapid prototyping of TM2+:II-VI materials by means of pulsed laser deposition (PLD) technology. The expected outcome of these activities can yield a new class of optically active thin film materials, and the fundamental understanding of their growth mechanism from dense fluxes of evaporated species.

· REU project will be focused on properties relevant to laser performance – detailed structure of the optical centers, their optical properties as a function of chemical composition and lattice parameters, measurements of radiative and multiphonon relaxation rates, absorption and emission cross-sections, emission quantum yields, study of possible excited state absorption.

· REU student will build a laser in the mid IR by choosing an appropriate laser material, pump source and high reflectors and then characterize the laser output (threshold, gain, power and beam profile).

9 REU students participated in REU projects related to study of laser crystals and laser spectroscopic characterization of materials relevant to laser physics, biomedicine and environmental research. Several REU publications have resulted from these efforts [11-14].