Effect of anisotropy of a single-mode fibre on lightning-induced rotation of polarisation of a light signal in an optical ground wire

A numerical model is constructed for calculating lightning-induced rapid changes in the polarisation state of a light signal at the output of a fibre-optic communication line with an optical ground wire. It is shown that taking into account anisotropy of real optical fibres has a noticeable effect on the shape of the polarisation rotation speed time profile. It is found that the maximum rate of change in the polarisation state and its temporal profile depend on the location of the lightning strike in the fibre span, the magnitude of fibre anisotropy and the direction of propagation of a light wave.

Gold Enhanced Graphene-Based Photodetector on Optical Fiber with Ultrasensitivity over Near-Infrared Bands

Graphene has been widely used in photodetectors; however its photoresponsivity is limited due to the intrinsic low absorption of graphene. To enhance the graphene absorption, a waveguide structure with an extended interaction length and plasmonic resonance with light field enhancement are often employed. However, the operation bandwidth is narrowed when this happens. Here, a novel graphene-based all-fiber photodetector (AFPD) was demonstrated with ultrahigh responsivity over a full near-infrared band. The AFPD benefits from the gold-enhanced absorption when an interdigitated Au electrode is fabricated onto a Graphene-PMMA film covered over a side-polished fiber (SFP). Interestingly, the AFPD shows a photoresponsivity of >1 × 104 A/W and an external quantum efficiency of >4.6 × 106% over a broadband region of 980–1620 nm. The proposed device provides a simple, low-cost, efficient, and robust way to detect optical fiber signals with intriguing capabilities in terms of distributed photodetection and on-line power monitoring, which is highly desirable for a fiber-optic communication system.

THE ARCTIC: THE TRANSPORT AND TELECOMMUNICATION OF INFRASTRUCTURE, THE ECONOMY, NATIONAL SECURITY

At the current time, it is impossible to manage the economy of the Russian Arctic zone regions without creating an infrastructure that will allow organizing effective management of the entire complex of industries located in these territories. In order to organize the development of the territory and living conditions on it, it is necessary to create the infrastructure and environment for comfortable living of the employed and residing population. First of all, it concerns the necessity to strengthen integration processes as the population living there experiences discomfort from the impossibility to use modern telecommunication and information services. In this article the author analyzes and proposes the concept of development and use of fiber-optic communication lines, which could provide (after their installation) the most inhabited communities with digital economy services at affordable prices. The population living in the northern regions and working in hydrocarbon production companies is partially provided with modern services through the construction of departmental communication lines for the management of production and transportation complexes. Get the integration of regional management systems based on the development of digital economy from the laying of Russian communication lines, replacing the use of satellite Internet owned by foreign companies. This will help to use information resources more efficiently in the process of management and interaction to solve common tasks of the Russian Arctic zone where the population lives on a permanent basis. In addition, the most important part of the construction of modern communication lines in the Arctic is to ensure the country’s defense capability of its northern borders, protection of the Northern Sea Route - the main route for the delivery of liquefied gas to Europe and Asia.

Design and Experimental Research of a Fiber-Optic Communication Module for Well Logging

Fiber-optic transmission has been applied in oil and gas industry over the years. Compared with other methods applied in the industry, fiber-optic transmission has the advantages of low loss, long-distance, high-capacity and robust to the electromagnetic interference. The ability to provide reliable transmission systems in the harsh environments like high temperatures is the key driver for the continued use of fiber-optic communication for in-well applications. We design a fiber-optic communication system under high temperatures for well logging applications. It consists of high-temperature laser diode, high-temperature photodetector with photoelectric detection circuit, drive control circuit, and field-programmable gate array (FPGA) as the communication chip. This system ensures that data can be transmitted at a rate of 15 Mbps at temperatures up to 155°C. The FPGA board makes the system to control data transmission flexibly and enable the serial communication between the photoelectric module and the host computer. Additionally, the number of fibers used in fiber-optic communication in logging will be reduced to only a single fiber for transmitting and receiving. A series of experiments on the performance and effects of fiber-optic communication at different temperatures was carried out. Data transceiver tests and eye diagram tests are presented. The experimental results demonstrated that this fiber-optic communication system is capable of working steadily over a long period of time in harsh environments around 155°C to realize broadband and remote transmission of logging information. This system provides a way that allows optical information to transmit in a high-temperature environment. It can be applied to well logging and fiber-optic sensing (e.g., real-time environmental parameters transmission, fiber-optic well monitoring) for developing real-time, high-data-rate, bidirectional fiber-optic communication in the future.