Work

Surface mechanics of GaAsP/GaAs epilayers for non-linear optical devices

Year: 2025

Type: article

Abstract: We report on nanoindentation measurements of hydride vapor phase epitaxy (HVPE) grown Gallium Arsenide Phosphide (GaAs 1-x P x ) epilayers, of interest for generation of mid-infrared wavelengths via frequency conversion. Our results indicate a linear trend in Young's modulus with increasing phosphorus content (P-content), in keeping with Vegard’s Law for ternary compounds. The corresponding data for hardness demonstrate significant bowing with a peak of 10.7 GPa occurring at 78% P-content. Some epilayers exhibit non-negligible spatial variation in their mechanical properties, which is investigated with complementary measurements. Photoluminescence measurements indicate high composition uniformity, while atomic force microscopy reveals a direct correlation between surface roughness and mechanical variability. Preliminary laser-induced damage threshold (LIDT) results are reported, and the implications for material optimization are discussed. With a 1070-nm continuous wave laser, GaAs 0.75 P 0.25 and GaAs 0.52 P 0.48 epilayers demonstrated LID thresholds of 600 kW/cm 2 and 300 kW/cm 2 , respectively.

Source: Optical Materials X

DOI: 10.1016/j.omx.2025.100420

Authors: Samuel M. Linser, Shivashankar R. Vangala, Harris J. Hall, Duane Brinegar, Timothy A. Prusnick, Vladimir L. Tassev

Institutions: United States Air Force Research Laboratory, KBR (United States), U.S. Air Force Research Laboratory Sensors Directorate

Language: English

Topic: Metal and Thin Film Mechanics

Subfield: Mechanics of Materials

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funders: Sensors Directorate, Air Force Office of Scientific Research, Air Force Research Laboratory