Photonic Crystal Fiber Sensors, Literature Review, Challenges, and Some Novel Trends

— This paper introduces an introduction to photonic crystals (PCs) and photonic crystal fiber (PCF) sensors along with their different applications. A comparative study of different types of PCF sensors including chemical, biomedical, and liquid sensors is presented. Many distinct factors, including the device structure, background material, operating wavelength, PCF's guiding mechanisms and the sample refractive indices to be detected, affect how PCF sensors behave. Different topologies such as hexagonal, hollow rectangle, decagonal, rectangular porous core, and mono rectangular are discussed. Sensing properties, and measurement methodologies for each of these sensors are discussed. Based on this comparative study, PCF sensors are categorized according to their properties, topologies, measurement techniques, and applications. The appropriate topology for the required application can be selected based on the required properties. The same PCF topology can be used for different sensing purposes. A comparative study of different types of PCF sensors in a form of table is presented followed by the challenges and some novel trends on Photonic Crystal Fiber. _______________________________________________________