Fabrication method of silicon nanostructures by anisotropic etching

A fabrication method of silicon nanostructures is presented. Silicon nanowire, shift-line structure and islands have been successfully fabricated on SOI wafer using e-beam lithography and anisotropic etching technique.

Effect of reconstruction beam polarization on the kinetics of anisotropic gratings in bacteriorhodopsin

Anisotropic gratings are recorded on bacteriorhodopsin films by two parallelly polarized beams, and the effect of the polarization orientation of the reconstructing beam on the diffraction efficiency kinetics is studied. A theoretical model for the diffraction efficiency kinetics of the anisotropic grating is developed by combining Jones-matrix and photochromic two-state theory. It is found that the polarization azimuth of the reconstructing beam produces a cosine modulation on the kinetics of the diffraction efficiency, being positive at the peak efficiency and negative for steady state. By adding auxiliary violet light during grating formation, the saturation of the grating can be restrained. As a result, the negative cosine modulation for the steady-state diffraction efficiency changes to a positive one. In addition, the steady-state diffraction efficiency is increased appreciably for all reconstructing polarization orientations. (c) 2008 Optical Society of America.

Spectroscopic properties of anisotropic absorption in a neodymium-doped YAlO3 laser crystal

Absorption spectra of YAlO3:Nd for the three crystallographic axes are investigated at room temperature, The spectral strengths indicate that the absorption coefficient of YAlO3:Nd is anisotropic. The anisotropy of the local electric field acting on the rare-earth ion in a laser crystal is considered, An extended Judd-Ofelt theory is applied to calculate the absorption cross sections and oscillator strengths of the electric-dipole transitions in the different principal directions. Three groups of the phenomenological parameters are derived from a least-squares-fitting procedure. We also analyze theoretically the anisotropy of the optical absorption of YAlO3:Nd crystal in detail. (C) 1997 American Institute of Physics.

Anisotropic strain in (100) ZnSe epilayers grown on lattice mismatched substrates

We show that part of the reflectance difference resonance near the E-0 energy of ZnSe is due to the anisotropic in-plane strain in the ZnSe thin films, as films grown on three distinctly different substrates, GaAs, GaP, and ZnS, all show the resonance at the same energy. Such anisotropic strain induced resonance is predicted and also observed near the E-1/E-1+Delta(1) energies in ZnSe grown on GaAs. The theory also predicts that there should be no resonance due to strain at, the E-0+Delta(0) energy, which is consistent with experiments. The strain anisotropy is rather independent of the ZnSe layer thickness, or whether the film is strain relaxed. For ZnSe films with large lattice mismatch with substrates, the resonance at the E-1/E-1+Delta(1) energies is absent, very likely due to the poor crystalline quality of the 20 nm or so surface layer. (C) 2000 American Vacuum Society. [S0734-211X(00)05604-3].