Diagnostic stand for quality control of diffractive optical element manufacturing

A diagnostic stand has been created to study the parameters of laser radiation transformed by diffractive optical elements (DOE) designed for operation in the infrared range. The optical systems included in the stand allow recording the intensity distribution formed by the elements of micro-optics in different planes that is necessary to control the focusing quality and to estimate the focus depth. They also provide an opportunity to measure the DOE power efficiency. Experimental approbation of optical systems on the example of a reflecting binary cylindrical lens and a Fresnel lens has been carried out.This work has been carried out within the framework of the strategic academic unit ‘Nanophotonics, emerging technologies of Earth’s remote sensing and intellectual geoinformation systems’ of the Samara National Research University’s competitiveness improving program

Theoretical study of the photoconductivity mechanism of the structure “carbon nanotubes – silicon substrate”

The types of optical radiation photodetectors have been considered according to the operating principle. The photoconductivity mechanism of carbon nanotubes (CNTs) deposited on a silicon substrate has been investigated theoretically. A comparison of the CNTs band gap with illuminating beam the quantum energy has been conducted. The heating and cooling cycles under the influence of a distributed surface energy source have been simulated. It has been established that CNTs on a silicon substrate have thermal-type photoconductivity. The sensitive element of the IR sensor based on this structure can be classified as a bolometric type