2ND-HARMONIC GENERATION FROM CHALCOPYRITE-STRUCTURE SEMICONDUCTOR THIN-FILMS

We propose that thin films of tetragonal chalcopyrite-structure semico nductor media are promising nonlinear-optical (NLO) materials for the following reasons: Phase matching is possible with them in principle, they can be utilized in a waveguide geometry, and they are compatible with m-V substrates. We investigate the second-order NLO properties of chalcopyrite-structure CuInSe2 and CuGaSe2 thin films grown on GaAs(0 01), using optical second-harmonic (SH) generation at a fundamental wa velength of 790 nm. The SH intensities produced by approximately stoic hiometric CuInSe2 and CuGaSe2 thin films are similar to that of GaAs. The second-order optical nonlinearities are strongly curtailed in nons toichiometric thin films. (C) 1996 Optical Society of America