Optical Constants of Germanium in Spectral Region from 0.5 eV to 3.0 eV

Abstract

The optical constants for electropolished intrinsic germanium have been determined for the spectral region between 0.5 and 3.0 eV at 300 and 120°K. The technique is based on the determination of the ratio (R n = Ru/Ri at its minimum value and the precise measure of the pseudo-Brewster angle <PB at that minimum, after correction for the presence of an oxide layer. Six distinct spectral features are observed, 4 of which have been reported by other investigators. These 4 consist of the two doublets, one at the r point, the other at A, each with the spin-orbit splitting effect. The other features, at 1.74 and 1.94 eV (300°K), and 1.84 and 2.04 eV (120°K), are attributed to direct transitions Lz'-Li. A discussion of the optical constants in terms of the joint density of states is also given. A comparison is made between normal reflectance values as calculated from the optical constants and recent very precise experimental normal reflectance measurements. OPTICAL CONSTANTS OF Ge 563

Determination of optical constants: Derivative spectra from ellipsometric data

“…The existence of a M,-edge is in accordance with Potter's results [9], the experimental uncertainty however (see error-bars in the derivative spectra) prevents the determination of its spin-orbit-splitting. Type and energy of the transition suggest that it is the L-transition a t the zone-boundary in conformity with band-structure calculations.…”

“…3a and b together with measurements by Aspnes [4] and Potter [9], which were acconiplished ellipsometrically, however with some different experimental arrangements. The agreement is quite convincing, the following conclusions from the derivative spectra are not influenced by these small quantitative differences.…”

Dielectric engineering of Ge nanocrystal/SiO2 nanocomposite thin films with Ge ion implantation: Modeling and measurement

“…For the case of nc-Ge, E g is 3.4 eV based on the optical constants of Ge and e BULK is 16.2 [33]. Thus, the theoretical prediction of e ncÀGe for a given nc-Ge size can be obtained from Eq.…”

Advancements in semiconductor core optical fiber

“…The high refractive indices of the semiconductors [53][54][55][56][57] promote large numerical apertures from the oxide glass-clad semiconductor core optical fibers and, therefore, multi-mode operation for core sizes greater than about 2 lm at mid-wave infrared wavelengths. While many applications, discussed in Section 5, can utilize multi-mode fibers, it is valuable to consider options for achieving single-mode crystalline semiconductor core optical fibers.…”