There exists a problem with an in situ diagnostics of contamination of ethyl alcohol in a human being exhaled air. When ethyl alcohol in a mouth blowing (in a gaseous state) exists, the characteristic C–H stretch absorption bands in –CH₃ and –CH₂ – functional groups in ethanol (CH₃–CH₂–OH) appear at a wavelength of λ = 3.42 μm. To investigate the presence of ethyl alcohol in exhaled human air, the light beam of λ = 3.42 μm is passing through an air sample. If one alternately measures the intensity of the investigated beam and the reference, a percentage of ethanol in the air sample can be estimated using a sensitive nondispersive infrared (NDIR) system with a stable operating flow mass detector. To eliminate a mechanical chopper and noise generating stepper motors, a photonic chopper as a liquid crystal shutter for λ = 3.42 μm has been designed. For this purpose, an innovative infrared nematic liquid crystal mixture was intentionally prepared. The working mixture was obtained by a selective removal of CH bonds and its exchange by heavier polar substituents, what ensures a lack of absorption band of C–H bonds. The paper presents theory, concept and final experimental results of the infrared nematic liquid crystals mixture and the liquid crystal shutter for breathalyzer applications.

To study the influence of structural features of phthalocyanine (Pc) derivatives on their physico-chemical properties in bulk and thin films, 23 new phthalocyanines with different quantity and ratio of donor (alkyloxy-groups, in fragment “A”) and acceptor (Cl-, in fragment “B”) substituents in one molecule of the A₃B, ABAB and AABB types with varied length of alkyloxy-substituents and their metal complexes were designed and synthesized. A comparative analysis of spectral, mesomorphic and photoelectric properties of these mix-substituted phthalocyanines of a “push–pull” type was performed. It was shown that non-peripheral substitution by alkyloxy-fragments in hetero-substituted Pcs (similar to homo-substituted Pc) leads to red-shifting of the Q-band into near-IR region. The intensity of photoluminescence, position of peaks and their splitting are strongly connected with chemical structure of Pcs and the type of solvent. In contrast to non-mesogenic octyloxy-Pc (A4) having alkyloxy-substituents in non-peripheral positions, 22 of 23 synthesized compounds possess columnar mesomorphism. The change of donor–acceptor ratio can influence the type of mesophase. A new approach to the creation of materials for optoelectronics is proposed and implemented, which includes design of compounds possessing vitrification from mesophase with maintenance of a columnar order, absorption in the near IR-region of the spectrum and good performance electrophysical characteristics simultaneously.

Analysis is performed of the contemporary views on the effect of ion etching (ion-beam milling and reactive ion etching) on physical properties of HgCdTe and on the mechanisms of the processes responsible for modification of these properties under the etching. Possibilities are discussed that ion etching opens for defect studies in HgCdTe, including detecting electrically neutral tellurium nanocomplexes, determining background donor concentration in the material of various origins, and understanding the mechanism of arsenic incorporation in molecular-beam epitaxy-grown films.

We propose real time phase measurements in liquid crystals cells using Young's interferometer constructed with a new principle with possibility to control the distance between two point sources. The optical interference optical pattern is detected by a bicell photo-detector in a back Fourier focal plane. A phase modulation controlled by a monopixel liquid crystals’ cell placed in a reference arm of interferometer is observed as a dynamic shift of the fringes’ pattern in spatial domain. Concept of signals’ demodulation in the Fourier focal plane will be described using a new approach to the demodulation signals. In this work we evaluate the demodulation condition of our setup and we present measurements of a dynamic phase response for nematic liquid crystals and antiferroelectric liquid crystals cells.