AgInSe2 nanorods:: A semiconducting material for saturable absorber

AgInSe2 nanorods (NRs) with a diameter of 15 nm have been investigated for their nonlinear optical responses by using Z-scan and transient absorption techniques with femtosecond laser pulses of photon energy greater than the band gap. At excitation irradiance of 20 GW/cm(2), AgInSe2 NRs reveal saturation in the nonlinear absorption and optical Kerr nonlinearity with a recovery time determined to be a few tens of picoseconds. Such large saturable absorption and Kerr nonlinearity exhibit a third-order susceptibility of 1.2x10(-8) esu and a figure of merit of 0.04 esu cm s(-1), making AgInSe2 NRs a promising candidate for saturable absorption devices. (c) 2007 American Institute of Physics.