Abstract

The authors report room-temperature measurements of the third order nonlinear susceptibility modulus parallel to chi((3))parallel to of thick (similar to 600 nm) InN layers. Transmission measurements provide a room-temperature value for the optical band gap of the samples slightly above 1500 nm. Third order nonlinear optical susceptibility has been measured using degenerate four wave mixing experiments at wavelengths near and above band gap. parallel to chi((3))parallel to values of (4.2-10)x10(-10) esu were measured at this wavelength range. The associated relaxation time of the generated population grating at 1500 nm was measured. The obtained value of 4.8 ps is consistent with a nonradiative recombination mechanism.(c) 2007 American Institute of Physics.