Title

Measurements of Nonlinear Optical and Damage Properties of Selected Contemporary Semiconductor Materials

Date of Award

2023

Degree Name

Ph.D. in Electro-Optics

Department

Department of Electro-Optics and Photonics

Advisor/Chair

Shekhar Guha

Abstract

Characterization of nonlinear optical properties of materials is important for high power, high energy laser material interactions. This work investigates the interaction of laser light with select semiconductor materials of interest. Fundamental parameters, functionality and limits are explored over a wide range of incident wavelengths and pulse durations. Both second and third order properties are considered, as well as laser damage. State-of-the-art materials with high second order nonlinear optical coefficients such as GaAs and CdSiP2 have been studied. Key applications of these materials are in generation of coherent mid-wave infrared radiation. Nonlinear frequency conversion in both have been attempted. Third order susceptibilities dictate the nonlinear absorption and refraction of a material. Here the nonlinear optical coefficients of two photon absorption, β, free carrier absorption, σ_a, and free carrier refraction, σ_r are established in gallium nitride (GaN) for the visible wavelength of 532 nm using picosecond and nanosecond pulse duration light. Free carrier recombination lifetime is also determined to ensure that the decay in the concentration of free carriers is not a factor for this material at nanosecond time scales.

Keywords

two-photon absorption, carrier recombination lifetime, frequency conversion, quasi phase matching, laser induced damage threshold, GaN, CdSiP2, orientation patterned GaAs

Rights Statement

Copyright © 2023, Author

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