Measurement and modeling of infrared nonlinear absorption coefficients and laser-induced damage thresholds in Ge and GaSb

Authors

Torrey J. Wagner, Air Force Institute of TechnologyFollow
Matthew J. Bohn, Air Force Institute of Technology
Ronald A. Coutu Jr., Air Force Institute of Technology
L. P. Gonzales, Air Force Research Laboratory
J. M. Murray, Air Force Research Laboratory
K. L. Schepler, Air Force Research Laboratory
S. Guha, Air Force Research Laboratory

Document Type

Article

Publication Date

10-1-2010

Abstract

Using a simultaneous fitting technique to extract nonlinear absorption coefficients from data at two pulse widths, we measure two-photon and free-carrier absorption coefficients for Ge and GaSb at 2.05 and 2.5 µm for the first time, to our knowledge. Results agreed well with published theory. Single-shot damage thresholds were also measured at 2.5 µm and agreed well with modeled thresholds using experimentally determined parameters including nonlinear absorption coefficients and temperature dependent linear absorption. The damage threshold for a single-layer Al₂O₃ anti-reflective coating on Ge was 55% or 35% lower than the uncoated threshold for picosecond or nanosecond pulses, respectively.

Comments

© 2010 U.S. Government.

DOI

10.1364/JOSAB.27.002122

Source Publication

Journal of the Optical Society of America B

Recommended Citation

T. J. Wagner, M. J. Bohn, R. A. Coutu, Jr., L. P. Gonzalez, J. M. Murray, K. L. Schepler, and S. Guha, "Measurement and modeling of infrared nonlinear absorption coefficients and laser-induced damage thresholds in Ge and GaSb," J. Opt. Soc. Am. B 27, 2122-2131 (2010)