Design of optical components for terahertz/sub-terahertz imaging systems

The possibility of using the lenses with an aspherical surface for terahertz/sub-terahertz (THz/sub-THz) imaging systems has been considered. Diffraction-limited optical system of four identical plano-convex aspheric lenses has been obtained. Tests of the lenses have been performed on the specially made stand. These calculated and experimental data have similar values, which confirms the use of such lenses in the THz/sub-THz imaging systems

Detection of IR and sub/THz radiation using MCT thin layer structures: design of the chip, optical elements and antenna pattern

Two-color un-cooled narrow-gap MCT (mercury-cadmium-telluride) semiconductor thin layers, grown by liquid phase epitaxy or molecular beam epitaxy methods on high resistivity CdZnTe or GaAs substrates, with bow-type antennas were considered both as sub-terahertz direct detection bolometers and 3...10-micrometer infrared photoconductors. Optical system with aspheric THz lenses were designed and manufactured. An antenna pattern of structures on the thick substrate was discussed, and sensitivity of detector in both IR and sub-THz regions was measured

In–HgCdTe–In structures with symmetric nonlinear I–V characteristics for sub-THz direct detection

This paper reports on the development and investigations of In–Hg1–xCdxTe–In structures with symmetric nonlinear I–V curves that are sensitive to sub-terahertz radiation. It is shown that at low currents photoresponse of the detectors based on these structures is due to the presence of potential barriers at the contacts. The dependences of the photoresponse as the function of the bias current are measured at the radiation frequency = 140 GHz in 77–300 K temperature range. The studied structures may be used as the detectors of sub-terahertz radiation at room temperature or under weak cooling. The calculated NEP of investigated In–n-Hg0.61Cd0.39Te–In detectors was 3.5•10–9 W/Hz1/2, if taking into account thermal and shot noise