Comprehensive solution for onboard fiber-optic information networks

Problem statement. In recent years, the problem of replacing copper-core fiber-optic cables has become particularly relevant. This is due to two factors: first, the prospect of introducing unmanned vehicles and the development of electromagnetic microwave weapons that can disable electronic equipment for almost any target at a distance of 10 km or more, and second, the growing need to reduce the delay of transmitted signals on the network and increase the volume of information transmitted in these networks. The article describes the construction of onboard cable networks using fiberoptic cables. The advantages and disadvantages of fiber-optic based onboard networks are described.Objective. Development of solutions for the use of fiber-optic communication cables in onboard information networks that provide high technology for laying optical cables, the required speed of information transmission, ease of operation and modernization of information networks.Results. A comprehensive solution for building onboard information networks based on fiber-optic cables having an increased core diameter and an optimized refractive index profile in pipelines using pneumatic laying technology is proposed.Practical implications. The proposed integrated solution for onboard fiber-optic information networks, including a method for onboard laying optical cables, the use of specially developed optical fiber with an increased core diameter and reduced differential modal delay, and the development of modular telecommunications equipment, allows meeting the requirements for onboard networks to ensure reliability and safety, economic efficiency, reduce labor intensity, and ease of maintenance, components dismantling and replacement

TECHNOLOGICAL ASPECTS OF MANUFACTURING SILICA OPTICAL FIBERS WITH LARGE CENTRAL DEFECT OF GRADED REFRACTIVE INDEX PROFILE FOR FIBER OPTIC SENSORS BASED ON FEW-MODE EFFECTS

The paper deals with results of the study on the main technological aspects relating to a full production cycle of silica multimode graded-index fibers with the refractive index profile having central defect in the form of a large dip. Preform synthesis conditions for implementation of the mentioned defect via MCVD method have been analyzed and optimized. We have carried out research of the effect of geometrical irregularities, induced by drawing optical fibers under the manual control of the outer diameter stability, on attenuation coefficient of the graded-index 50/125 μm optical fibers with a large dip in the center of the refractive index profile. It is shown that variations of the outer diameter within the limits ± 3.5 μm lead to an increase of attenuation by 2–5 dB/km at the wavelength λ = 1310 μm as compared to the optical fibers fabricated under the automatic maintenance of the outer diameter stability. It has been determined that in the latter case fibers with the parabolic refractive index profile, corresponding to numerical aperture of 0.20, and the dip depth equal to 0.0115 demonstrate the attenuation about 5 dB/km in the second and third optical fiber transmission windows. Applying the Weibull distribution, a statistical evaluation of mechanical properties of the optical fibers drawn at various temperatures has been carried out. Based upon measurements, tensile strength of the fibers was estimated to be 5.07–5.49 GPa, that is comparable with the strength properties of silica telecom fibers. The manufactured multimode fibers are attractive candidates for developing sensing elements of registering external influences in systems of fiber-optic sensor networks based on few-mode effects