Optical Mueller matrix modeling of chiral Al(x)In(1− x)N nanospirals (original) (raw)

Structure-Induced Optical Anisotropy in Thin Films

Thesis the University of Arizona 1983 Source Dissertation Abstracts International Volume 44 11 Section B Page 3447, 1983

We consider in this work the contribution of anisotropic microstructure to polarization effects in thin films. The microstructure is pictured by a simple model as composed of identical columns with elliptical cross section elongated in a direction perpendicular to that of the vapor incidence. The asymmetry in columnar structure that results from oblique deposition is identified as the common source for the significant dichroism and birefringence observed in metal and dielectric films, respectively. A four-dimensional theory for multilayer systems is presented that starts from first principles, unifies previous treatments for particular cases of film anisotropy, and properly handles the most general case of elliptically polarized mode propagation. In this framework and from a set of polarimetric measurements, a simple method is devised, with explicit consideration of the anisotropic microstructure, for the determination of the physical thickness and principal refractive indices of a single dielectric film. A sequence of transmittance measurements is performed with a zirconium oxide film deposited at 65(DEGREES) and, substrate role and instrumental errors considered, good agreement is obtained between theory and experiment. Spectrophotometer data for a narrowband filter with 21 layers deposited at 30(DEGREES) is shown to confirm theoretical predictions of peak positions with Angstrom resolution. A hypothetical metal film is discussed that reproduces the essential features observed in the optical behavior of an aluminum film deposited at 85(DEGREES). Potential applications and suggestions for future work are included.

Linear optical modeling on aluminum zig-zag thin films Sc Scientific research paper

JITL, 2022

The Al zigzag sculptured thin film consists of two identical columns, the first nanocolumns (zig) are oriented at the angle χ and the second nanocolumns (zag) are oriented at the angle (π-χ). The optical properties of these nanostructures were obtained using the transfer matrix method for linear sand p-polarized incident lights in the wavelength range of 300-1000 nm. The reflection and transmission spectra of the zigzag nanostructures with different arm numbers and lengths were obtained at different incident angles. The Bragg peaks begin to appear for zigzag nanostructures of more than 4 arms for s-polarized light at the angles greater than 30. For zigzag structures of 4, 8, and 16 arms, one, two, and three Bragg peaks were observed, respectively. However, for p-polarized light, no Bragg peak was observed at any of the incident angles. Also, for the zigzag structure of 8 arms for s-polarized light at 60 incident angles, the number of Bragg peaks increases with increasing the arm length. In addition, the peaks created in the wavelengths below 550 nm showed red shift while the peaks appeared in the wavelengths above 550 nm showed blue shift.

Optical properties of multilayer optics including negative index materials

Eprint Arxiv 1312 6288, 2013

Negative indices are revisited through the thin-film admittance formalism. Effective indices and phase delay associated with wave propagation through negative index layers are carefully defined and computational rules easily implementable in standard thin-film software are derived from this approach. This admittance formalism is then used to recover the main features of the perfect lens and to highlight the benefit of such negative index materials to improve the performances of quarter-wavelength Bragg mirrors and Fabry-Perot band-pass filters.