We propose that thin films of tetragonal chalcopyrite-structure semiconductor 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 III–V substrates. We investigate the second-order NLO properties of chalcopyrite-structure CuInSe2 and CuGaSe2 thin films grown on GaAs(001), using optical second-harmonic (SH) generation at a fundamental wavelength of 790 nm. The SH intensities produced by approximately stoichiometric CuInSe2 and CuGaSe2 thin films are similar to that of GaAs. The second-order optical nonlinearities are strongly curtailed in nonstoichiometric thin films.
© 1996 Optical Society of America
Original Manuscript: August 22, 1995
Published: February 15, 1996
D. J. Bottomley, A. Mito, S. Niki, and A. Yamada, "Second-harmonic generation from chalcopyrite-structure semiconductor thin films," Opt. Lett. 21, 254-256 (1996)