Nondegenerate two-photon absorption in GaSb

• Published in: Optics communications Vol. 304; pp. 54 - 57
• Main Authors: Olson, Benjamin V., Gehlsen, Michael P., Boggess, Thomas F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-09-2013
• Subjects: Beams (radiation); Dispersions; GaSb; Nondegenerate two-photon absorption; Nonlinear index of refraction; Nonlinearity; Optical nonlinearities; Polarization; Pumps; Refractive index; Time-resolved pump–probe; Transformations; Wavelengths; GaSb; Optical nonlinearities; Time-resolved pump–probe; Nonlinear index of refraction; Nondegenerate two-photon absorption
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2013.04.035

The nonlinear optical absorption of n-type GaSb at 77K was investigated using time-resolved pump–probe techniques. By holding the pump wavelength constant and varying the probe wavelength, the nondegenerate two-photon absorption spectrum was measured for parallel and perpendicular polarization orientations between the pump and probe beams. The nondegenerate two-photon absorption coefficients, which were measured to be as large as 140cm/GW, are found to be 2–3times smaller for the perpendicularly polarized case than in the parallel polarization case. A Kramers–Krönig transformation allowed the determination of the dispersion of the nondegenerate nonlinear refractive index, which was found to be as large as 2×10−3cm2/GW.