Abstract
We previously reported optical fourth-harmonic generation (FHG) in reflection from a GaAs(001) surface using 200-fs pulses, well below the damage threshold.1 The data revealed a strong fourfold anisotropic surface-specific polarization that is not present in second-harmonic generation (SHG) and that, surprisingly, was nearly as strong as the dipole-allowed, twofold anisotropic contribution from the noncentrosymmetric bulk. The unusual relative strength of the surface FH contribution suggested that surface-specific FHG could be observed by itself in reflection from a centrosymmetric crystal. In this work, we demonstrate azimuthally anisotropic FHG from a crystalline Si(001) interface using 5-μJ, 200-fs pulses at fluences >5× below the damage threshold. Our data indicate that the surface dipole FH contribution dominates over the bulk quadrupole FH contribution much more strongly than for the corresponding SHG contributions, thus making FHG from Si(001 ) one of the most purely surface-specific optical probes ever reported.
© 1998 Optical Society of America
PDF ArticleMore Like This
Y.-S. Lee, M. H. Anderson, and M. C. Downer
QWC6 Quantum Electronics and Laser Science Conference (CLEO:FS) 1997
A.A. Fedyanin, A.V. Melnikov, E.D. Mishina, A.N. Rubtsov, O.A. Aktsipetrov, M.H. Anderson, P.T. Wilson, M. ter Beek, X.F. Hu, J.I. Dadap, and M.C. Downer
QFH7 International Quantum Electronics Conference (IQEC) 1998
J. I. Dadap, X.F. Hu, M.H. Anderson, M.C. Downer, J.K. Lowell, and O.A. Aktsipetrov
FD3 International Quantum Electronics Conference (IQEC) 1996