PULSED-LASER DEPOSITION OF CU-AL2O3 NANOCRYSTAL THIN-FILMS WITH HIGH 3RD-ORDER OPTICAL SUSCEPTIBILITY

Nanocomposite films comprising metal Cu nanocrystals embedded in an Al 2O3 matrix were deposited by alternating pulsed laser ablation from me tallic Cu and ceramic Al2O3 targets. The films were grown in vacuum on glass substrates held at room temperature. The as-grown films contain 4 nm Cu nanocrystals in an amorphous Al2O3 matrix, with a total thick ness of 190 nm. The films show a substantial third-order susceptibilit y with an electronic nonlinear refractive index of (2.93 +/- 1.08).10( -10) cm(2) W-1 and a nonlinear saturation of -(2.34 +/- 0.18).10(-5) c m W-1. (C) 1997 American Institute of Physics. [S0003-6951(97)03743-1] .