Recent Advancement in Photonic Crystal Fiber Based Sensors: A Review.

This review paper summarizes properties, uses, working principle and applications of the Photonic Crystal Fiber and its comparison with conventional fiber. In simple terms, conventional optical fiber is a wired transmission medium that offers an optical channel that is more reliable as well as flexible than the atmosphere. The most crucial aspects of any communication systems are its bandwidth and signal-to-noise ratio, which determine the channel's capacity. At 1550 nm, the optical fiber link currently has a loss of 0.2 dB/km. A single fiber-optic communication link has a bandwidth of about 50 THz. Thus, the foundation of modern communication systems is made up of fiber optic communication systems. Optical fiber is used in a wide range of sensor applications in addition to communication. However, optical fiber is not able to offer design flexibility. Thus, Photonic Crystal Fiber--a desirable substitute fiber--came into existence. With only little changes to its geometrical dimensions, photonic crystal fiber offers exceptional design freedom and opens opportunities in various sensing applications. This article covers comparative analysis of different sensing parameters like birefringence, confinement loss for liquids mediums like water, ethanol, benzyne, glucose solution, human mucosa etc. The geometrical structural dependence of sensitivity of PCF based sensors have been reviewed. Further, for different gases their absorption wavelengths, relative sensitivity, confinement loss at different operating frequencies sensitivity and effective mode area have been reviewed. Performance parameters of PCF-based temperature sensors for different PCF designs have also been analysed. It is suggested that by adjusting the geometrical structure of air holes the performance of PCF based sensors can be optimized. [ABSTRACT FROM AUTHOR]