Optical fibre sensors are an essential subset of optical fibre technology, designed specifically for sensing and measuring several physical parameters. These sensors offer unique advantages over traditional sensors, making them gradually more valuable in a wide range of applications. They can detect extremely small variations in the physical parameters they are designed to measure, such as analytes in the case of biosensing. This high sensitivity allows them to detect subtle variations in temperature, pressure, strain, the refractive index of analytes, vibration, and other environmental factors with exceptional accuracy. Moreover, these sensors enable remote sensing capabilities. Since light signals are used to carry information, the sensing elements can be placed at distant or inaccessible sites and still communicate the data back to the central monitoring system without signal degradation. In recent times, different attractive configurations and approaches have been proposed to enhance the sensitivity of the optical fibre-based sensor and are briefly explained in this review. However, we believe that the choice of optical fibre sensor configuration should be designated based on the specific application. As these sensors continue to evolve and improve, they will play an increasingly vital role in critical monitoring and control applications across various industries.
Keywords: D-shaped fibre; S-shaped fibre; U-shaped fibre; biosensing; fibre Bragg grating; optical fibre; photonic crystal fibre; photonic sensor; plastic optical fibre.