The basic optical properties and optical constants of the ionomer thin film have been investigated by means of transmittance and reflectance spectra. The real (n) and imaginary (k) parts of the complex refractive index and dielectric constant of the thin film were determined. The oscillator energy Eo, dispersion energy Ed and other parameters have been determined by the Wemple– DiDomenico metho...

The inter-band optical absorption in graphene characterized by its fine-structure constant has a universal value of 2.3% independent of the material parameters. However, for several graphenebased photonic applications, enhanced optical absorption in graphene is highly desired. In this work, we quantify the tunability of optical absorption in graphene via the Fermi level in graphene, angle of in...

Stable films containing CdS quantum dots of mean size 3.4 nm embedded in a solid host matrix are prepared using a room temperature chemical route of synthesis. CdS/synthetic glue nanocomposites are characterized using high resolution transmission electron microscopy, infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. Significant blue shift from the bulk abs...

Exploring the interactions between light and nanostructures contributes greatly to understanding and engineering nanoscale optical phenomena related to device performance. However, this often involves a compromise between uniformity and scalability. Given that optical properties, and especially light absorption, are governed by the geometries of nanostructures, this study investigated the corre...

We present density-functional theory calculations of the optical absorption spectra of silica glass for temperatures up to 2400 K. The calculated spectra exhibit exponential tails near the fundamental absorption edge that follow the Urbach rule in good agreement with experiments. We discuss the accuracy of our results by comparing to hybrid exchange correlation functionals. We show that the Urb...

In the preceding paper (paper I), we presented HI absorption spectra towards radio sources very close to the lines of sight towards 25 bright stars against which optical absorption spectra had been obtained earlier. In this paper we analyse the results and draw some conclusions. To summarize briefly, in most cases we found HI absorption at velocities corresponding to the optical absorption feat...

Organic carbon (OC) accounts for a large fraction of particulate matter. Since many atmospheric organic compounds have different optical properties, it is difficult to determine the optical properties of OC accurately. In particular, hygroscopicity and light absorption of OC are important factors in understanding the aerosol optical properties. In this study, the sensitivity of organic carbon (...

We report on the design, fabrication and optical characterization of GaN/AlN quantum-dot-based waveguides for all-optical switching via intraband absorption saturation at 1.55 µm. The transmittance of the TM-polarized light increases with the incident optical power due to the saturation of the s-p(z) intraband absorption in the QDs. Single-mode waveguides with a ridge width of 2 µm and a length...

We have performed non-invasive, real-time optical mapping of the piglet brain during a subcortical injection of autologous blood. The time resolution of the optical maps is 192 ms, thus allowing us to generate a real-time video of the growing subcortical hematoma. The increased absorption at the site of blood injection is accompanied by a decreased absorption at the contralateral brain side. Th...

Objectives: In this article, a new procedure for increasing the light penetration depth in a tissue is studied and simulated. It has been reported that the most important problem in biomedical optical imaging relates to the light penetration depth, and so this makes a dramatic restriction on its applications. In the optical imaging method, the detection of the backscattered pho...