Semicond. Physics Quantum Electronics & Optoelectronics, 2014, № 2

Hybrid-integrated version of solid-state components for terahertz frequency region

Wed, 01 Jan 2014 00:00:00 GMT

Hybrid-integrated version of solid-state components for terahertz frequency region Zorenko, O.V.; Bychok, A.V.; Kryts’ka, T.V.; Kudryk, Ya.Ya.; Shynkarenko, V.V. We present the results of development of key components for THz devices obtained using mathematical modeling of detector sections, radiation source and subharmonic mixers. Schottky barrier diodes with different parameters served as nonlinear elements of the above facilities.

Intrinsic concentration dependences in the HgCdTe quantum well in the range of the insulator-semimetal topological transition

Wed, 01 Jan 2014 00:00:00 GMT

Intrinsic concentration dependences in the HgCdTe quantum well in the range of the insulator-semimetal topological transition Melezhik, E.O.; Gumenjuk-Sichevska, J.V.; Dvoretskii, S.A. The band structure and dependences of the intrinsic concentration in the mercury-cadmium-telluride (MCT) Hg₀.₃₂Cd₀.₆₈Te/Hg₀ Cd₀ Te/Hg₀.₃₂Cd₀.₆₈Te quantum wells in the framework of the 8x8 k.p envelope function method on the well width L and composition x were calculated. Modeling of the energy spectra showed that the intrinsic concentration can vary about an order of magnitude with variation of the well width and chemical composition in the range of x < 0.16 and well width L < 20 nm at the liquid nitrogen temperature. These strong variations of the carrier concentration are caused by the insulator-semimetal topological transition.

Modification of optical properties and structure of thin films for enhancing absorption

Wed, 01 Jan 2014 00:00:00 GMT

Modification of optical properties and structure of thin films for enhancing absorption Lysiuk, V.O. The most used methods such as ion implantation, laser irradiation and nanosphere lithography for modification and creation of special microrelief of thin absorbing films on photosensitive substrates have been described. Controlled modification of surface structure of the samples for improving their optical properties, especially for enhancing absorption, has many applications in optical devices. The basic things were analyzed from selection of film materials and ways for their further processing to shapes and dimensions of the obtained surface structures. Theoretical modeling methods based on the Mie theory and statistical temporal mode-coupled theory have been used to explain the influence of surface microrelief on optical properties of the samples. Advantages and perspectives for application of the methods have been described and analyzed.

Generation and enhancement of SRS sub-nanosecond pulses in self-focusing organic substances

Wed, 01 Jan 2014 00:00:00 GMT

Generation and enhancement of SRS sub-nanosecond pulses in self-focusing organic substances Isaenko, O.Iu.; Ivanisik, A.I.; Korotkov, P.A.; Ponezha, G.V. The possibility to use self-focusing organic substances in order to create highly efficient transformers of laser radiation based on stimulated Raman scattering has been researched. The proposed and implemented optical schemes are suitable for generation of seed sub-nanosecond Stokes pulses, due to dynamics of self-focusing, and the compression of giant pulses of multimode laser with high (>20) increase in the intensity at a shifted frequency