相关论文: Optical absorption of silicon nanowires
When calculating the optical absorption spectra of molecular crystals from first principles, the influence of the crystalline environment on the excitations is of significant importance. For such systems, however, methods to describe the…
Coating and reflecting thin films for energy harvesting purposes are interesting topics in both theoretical and experimental research. The thin film could help to enhance the absorption of the system via its specific optical properties…
We investigate the relaxation dynamics of photogenerated carriers in silicon nanowires consisting of a crystalline core and a surrounding amorphous shell, using femtosecond time-resolved differential reflectivity and transmission…
Silica (SiO$_2$) nanotubes (NTs) are used in a wide range of applications that go from sensors to nanofluidics. Currently, these NTs can be grown with diameters as small as 3 nm, with walls 1.5 nm thick. Recent experimental advances…
Phonon properties of small Si nanowires in [110] direction have been analyzed using density functional perturbation theory. Several samples with varying diameters ranging from 0.38 to 1.5 nm have been calculated. It is found that the…
A general framework for determining fundamental bounds in nanophotonics is introduced in this paper. The theory is based on convex optimization of dual problems constructed from operators generated by electromagnetic integral equations. The…
We investigate the specific optical regime occurring at short wavelengths, in the high absorption regime, in silicon thin-films patterned by periodically arranged nano-holes. Near-field scanning optical microscopy indicates that the…
We evaluate the rate of the absorption of an optical nanofiber mode by a Cs atom in an electric quadrupole transition. With the Cs atom localized near the outer surface of the optical nano-fiber, an interaction occurs between the atomic…
Optical absorption spectra of higher fullerenes (C70 and C76) as well as of C60 are calculated by a tight binding model with a long range Coulomb interaction. A reasonable parameter set gives calculated spectra which are in overall…
Third-order bound-charge electronic nonlinearities of Si nanocrystals (NCs) embedded in a wide band-gap matrix representing silica are theoretically studied using an atomistic pseudopotential approach. Nonlinear refractive index, two-photon…
We present a method for the measurement of small optical absorption coefficients. The method exploits the deformation of cavity Airy peaks that occur if the cavity contains an absorbing material with a non-zero thermo-refractive coefficient…
Laboratory measurements of unpolarized and polarized absorption spectra of various samples and crystal stuctures of silicon carbide (SiC) are presented from 1200--35,000 cm$^{-1}$ ($\lambda \sim$ 8--0.28 $\mu$m) and used to improve the…
Ultraviolet photodesorption of molecules from icy interstellar grains can explain observations of cold gas in regions where thermal desorption is negligible. This non-thermal desorption mechanism should be especially important where UV…
Experimental and theoretical results are presented for double, triple, and quadruple photoionization of Si$^+$ and Si$^{2+}$ ions and for double photoionization of Si$^{3+}$ ions by a single photon. The experiments employed the photon-ion…
Absorption measurement is an exceptionally versatile tool for many applications in science and engineering. For absorption measurements using laser beams of light, the sensitivity is theoretically limited by the shot noise due to the…
We analyze the rate of two-photon absorption in tapered optical fibers with diameters less than the wavelength of the incident light. The rate of two-photon absorption is shown to be enhanced due to the small mode volume of the tapered…
We present a method for computing optical absorption spectra by means of a Bethe-Salpeter equation approach, which is based on a conserving linear response calculation for electron-hole coherences in the presence of an external…
Configurations capable of maximizing both absorptance and polarization contrast were determined for 1550 nm polarized light illumination of different plasmonic structure integrated superconducting nanowire single-photon detectors (SNSPDs)…
In this paper we show that the sensitivity of absorption imaging of ultracold atoms can be significantly improved by imaging in a standing-wave configuration. We present simulations of single-atom absorption imaging both for a…
This work focuses on the characterization of various bulk silicon (Si) samples using Fourier Transform InfraRed (FTIR) and grating spectrometers in order to get them suitable for applications in astronomy. Different samples at different…