MEASUREMENT OF NONLINEAR REFRACTION INDEX AND 2-PHOTON ABSORPTION IN A NOVEL ORGANOMETALLIC COMPOUND

We have determined the nonlinear refraction index [n(2) = -(6.6 +/- 0. 7) x 10(-11) cm(2)/W] and two-photon absorption (TPA) coefficients [be ta = (4.5 +/- 0.4) x 10(-8) cm/W] of a new kind of organometallic comp ound [Tp Ir(CHCHC(CH3)(NH)(C2H5))] in dilute CH2Cl2 (1 x 10(-3) M) so lution. The experiments where performed with a nanosecond-pulsed Nd-YA G laser at its second harmonic (lambda = 532 nm) radiation and employi ng the single- and dual-beam Z-scan techniques. The beam polarization, wavelength dependence and fast response time (tau < 7 ns) of the effe ct indicate that the observed nonlinearity near resonance is of electr onic origin. This material also shows a good figure of merit [(2 beta lambda)/n(2) = 0.07] for its applications in all-optical devices in th e nanosecond regime. Additionally, this organometallic is easy to synt hesize, stable and exhibits no toxic and no pollutant properties. (C) 1998 Published by Elsevier Science B.V. All rights reserved.