A holographic wavefront sensor based on the Talbot effect is proposed. Optical wavefronts are measured by sampling the light amplitude distribution with a two-dimensional (2D) precorrected holographic grating. The factors that allow changing an angular measurement range and a spatial resolution of the sensor are discussed. A comparative analysis with the Shack-Hartmann sensor is illustrated with some experimental results.

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OPTICAL AND ELECTROPHYSICAL PROPERTIES OF 95% In 2 O 3 + 5% SnO 2 /ns-Si HETEROSTRUCTURE PACS 68.37 Hk, Optical and electrical properties of 95% In2O3 + 5% SnO2/ns-Si heterostructures with films 6 and 12 nm in thickness deposited on a nanostructured silicon surface by the magnetron sputtering have been considered. It is shown that the 6-nm film is characterized by several peaks in the optical absorption spectrum, while the 12-nm film has no absorption peaks in the same spectral interval. The influence of the environment and the optical irradiation on the electrical properties of 95% In2O3 + 5% SnO2/ns-Si structures is determined. Their response to the gas environment is shown to be governed by the dielectric permittivity of an adsorbate. The results obtained can be used in the development of resistive gas sensors based on 95% In2O3 + 5% SnO2/ns-Si films.K e y w o r d s: current-voltage characteristics, absorption spectrum, thin films, transparent oxides.

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Electrophysical characteristics of gas-sensitive Ni -(95% In2O3 + 5% SnO2)p-Si heterojunctions have been studied experimentally. The analysis of their current-voltage characteristics (CVCs) registered in various gas environments reveals a significant increase of the reverse current through specimens in the atmosphere of ethanol or isopropyl vapor. Various mechanisms of current flow through the heterojunction are considered to explain this phenomenon. Variations in the potential barrier height under the action of image forces are demonstrated to play a significant role in shifts of the reverse CVC branches of examined specimens. The image force changes are explained by the influence of the adsorbate on the dielectric permittivity of oxide films.