Long Distance Military Fiber-Optic Polarization Sensor Improved by an Optical Amplifier

Abstract

The ever-increasing demands for the use of fiber-optic sensors powered by long optical fibers is forcing developers to solve problems associated with powering these remote sensors. Due to their non-electric character, these sensors are suitable for many uses, including military applications. The Army of the Czech Republic is very interested in this type of optical fiber sensor as it fulfils the significant prerequisites for use in military areas. However, the army’s requirements are challenging because they require long supply cables in which there is significant attenuation of optical power. At the same time, there is a need for high sensitivity. The subject of our research team’s work was to use amplifiers to power these sensors. The army already uses this type of sensor for short distances as it cannot ignite a gas mixture with an explosive concentration and thus meet the strict requirements of the explosion-poof standard. The novelty of our research lies in the discovered measurement technique that allows the sensors to be powered remotely and in the saving of optical fibers by utilizing duplex communication with a circulator. Furthermore, the research presents an innovative approach to the optimization of the entire sensor by using a bidirectional, sensory, polarization-maintaining optical fiber. The proposed sensor was first verified in laboratory conditions at the Optoelectronics Laboratory of the University of Defense in Brno, and further tests were carried out in the military training areas of Boletice and Březina in the Czech Republic, which is a member of North Atlantic Treaty Organization.

High-speed polarization fiber sensors optimized for security purposes

“…The research described here is based on a polarization maintaining fiber that causes the conversion of an external physical phenomenon into a change in the polarization state in the optical fiber. The principles have been described many times in our publications [1][2][3][4][5][6], while the final connection is shown in Figure 1.…”

“…This type of sensor is widely used in industry and scientific research where accurate temperature and pressure monitoring is needed in various environments. Thanks to the polarization-maintaining optical fiber, the sensor is resistant to external influences and enables reliable measurements even in demanding conditions [6]. Many other scientific studies deal with the issue of sensors and polarized light, for example utilizing POF polymer fibers [7], fiber Bragg gratings [8], or in combination with EDFA amplifiers [9].…”

Assessment of the Influence of Protective Polymer Coating on Panda Fiber Performance Based on the Results of Multivariant Numerical Simulation

“…Optical fiber is often used in sensor manufacturing to measure strain [5], applied loads [6], stress [7], magnetic field and temperature [8], etc. [9][10][11][12]. It has made life easier as it allows rapid assessment of the durability not only of structures [11] but also of the human body [9].…”