An updated tabulation is presented of the optical properties of intrinsic silicon relevant to solar cell calculations. the absorption coeficient, refractive index and extinction coeficient at 300 K are tabulated over the 0.25-1.45 μm wavelength range at 0.01 μm intervals.

Optical properties of intrinsic silicon at 300 K

Self-consistent optical parameters of intrinsic silicon at 300 K including temperature coefficients

We introduce the concept of metamaterial analog computing, based on suitably designed metamaterial blocks that can perform mathematical operations (such as spatial differentiation, integration, or convolution) on the profile of an impinging wave as it propagates through these blocks. Two approaches are presented to achieve such functionality: (i) subwavelength structured metascreens combined with graded-index waveguides and (ii) multilayered slabs designed to achieve a desired spatial Green's function. Both techniques offer the possibility of miniaturized, potentially integrable, wave-based computing systems that are thinner than conventional lens-based optical signal and data processors by several orders of magnitude.

http://science.sciencemag.org/content/sci/343/6167/160.full.pdf

Performing mathematical operations with metamaterials.

By applying the optical nanocircuit concepts to metasurfaces, we propose an effective route to locally control light transmission over a deeply subwavelength scale. This concept realizes the optical equivalent of a transmit-array, whose use is demonstrated for light bending and focusing with unprecedented efficiency over a subwavelength distance, with crucial benefits for nano-optics applications. These findings may lead to large improvements in the manipulation of optical transmission and processing of nanoscale optical signals over conformal and Si-compatible substrates.

Full control of nanoscale optical transmission with a composite metascreen.

The Centre of Excellence for Advanced Silicon Photovoltaics
and Photonics is supported under the Australian Research
Council’s Centres of Excellence Scheme. One author
(T.T.) would like to thank the Alexander von Humboldt foundation
for a Feodor Lynen-Scholarship while another
(M.A.G.) acknowledges the award of an Australian Government
Federation Fellowship.

/pdf/temperature-dependence-of-the-radiative-recombination-3djblge7d3.pdf

Temperature dependence of the radiative recombination coefficient of intrinsic crystalline silicon

The refractive indexes and their variations with temperature for silicon and germanium have been measured over the 95–298-K and 2.5–12-μm ranges. Data are given for the refractive index that are in reasonable agreement with those of previous investigators. For dn/dT the values are independent of wavelength and are approximately 1.5 × 10−4 (K)−1 and 4.0 × 10−4 (K)−1 for silicon and germanium, respectively.

Refractive indexes and temperature coefficients of germanium and silicon.

A simple method for measuring refractive index in the infrared is described. It uses autocollimation from the front surface of a prism and requires only that the receiver be moved to measure a new deviated ray when either the wavelength of the source or the temperature of the sample is changed. An error analysis that includes consideration of the evacuated sample space and wedge in the chamber windows shows that errors as low as one part in the fourth decimal place can be obtained.

Ben C. Platt

Papers

Refractive indexes and temperature coefficients of germanium and silicon.

Technique for measuring the refractive index and its change with temperature in the infrared