Communication based on scattered laser radiation in a medium with high turbidity or in the presence of a noise source

The results of laboratory studies of an optical communication channel based on scattered radiation in the Big Aerosol Chamber of IAO SB RAS in a clean atmospheric environment, in the case of the chamber filled with vapor of the water-glycerin mixture, and in the presence of an noise laser source are analyzed. It is found that with the non-coplanar communication geometry in the chamber filled with the water-glycerin mixture, stable data transmission is possible with the azimuthal angle of orientation of the detector optical axis up to 5°. The error probability in the communication channel increases more slowly with an increase of the detector elevation angle in the chamber filled with the water-glycerin mixture than that in the chamber without this mixture does. The presence of an interfering laser radiation at a wavelength λ = 510 nm in the communication channel affects the communication quality. When the power of the noise laser source achieves 70 mW, the maximal error probability corresponds to 0.02.

WIRELESS OPTICAL COMMUNICATION CHANNEL IN THE HYDROSPHERE AS AN ALTERNATIVE OF COMMUNICATION BY CABLE

В качестве альтернативы кабелю, авторами предложена методика управления с применением лазерной связи. Предлагаемые авторами решения позволят расширить возможности обмена информацией в гидросфере между подводными аппаратами. As an alternative to the cable, the authors have proposed a control technique based on the use of laser communication. The solutions proposed by the authors will expand the possibilities of information exchange in the hydrosphere between underwater vehicles.

DETECTION OF INFORMATION LEAKAGE THREATS IN FIBER OPTICAL COMMUNICATION CHANNEL

The paper discusses the possibility of detecting an information leakage channel in standard fiber-optic communications by monitoring optical radiation. Any abnormal light emission can create a potential threat of speech information leakage, as well as regular light streams modulated at acoustic frequencies.

Безошибочное различение когерентных состояний двухмодового оптического поля

The procedure of a quantum measurement, the unambiguous state discrimination, is studied for the case of four two-mode coherent states of the optical field, interesting for information transmission via an optical communication channel. It is shown that a complex conjugation of the amplitude of one of the modes results in a better distinguishability of the states. An interferometric scheme is suggested for unambiguous discrimination of such states and the probability of successful discrimination is found. Applications of the considered state set are discussed for quantum cryptography, quantum teleportation and optical communications with a high level of loss.