A series of specialised acousto-optic modulators/frequency shifters based on paratellurite (TeO2) single crystals is developed for systems of laser cooling and frequency stabilisation of laser sources in optical and microwave frequency standards based on cold strontium, rubidium and caesium atoms. The methods of calculation and optimisation of the main parameters of acousto-optic modulators are considered; their basic technical characteristics are experimentally investigated in the spectral range of optical radiation 460 – 900 nm and in the frequency shift range of 5 – 400 MHz. The modulators have a high diffraction efficiency, low power consumption and the ability to work with linearly and randomly polarised optical radiation.

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The falsification of drinks, syrups, extracts and concentrates, as a rule, is of a technological nature and is carried out by diluting, as well as completely or partially replacing natural ingredients with essences, sweeteners, colorants and other additives, including synthetic ones. Painted fruits are distinguished by the presence of anthocyanins - compounds that determine their color and have high antioxidant activity. The paper describe developments of libraries of spectra of artificial dyes used as additives in drinks and food products and of spectra of natural juices (containing anthocyanins) in the wavelength range of the visible part of the spectrum from 400 to 760 nm.

The main problems of metrological support of speed and throughput measurements in digital packet data networks are considered. The measures for performing data rate measurements are listed. Various ways of ensuring traceability of digital information transmission rate meters are proposed, such as modernization of the existing GET 200-2012, development of the primary reference method of speed measurements and creation of a local verification scheme for digital information transmission rate measurements. Recommendations on the implementation of the chosen method of ensuring traceability of data rate meters and throughput of communication channels are given. The proposed approaches can be applied in the Metrology of digital communication systems.

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