Photonic crystal fiber pressure sensors

This chapter introduces photonic crystal fibers (PCFs) specifically designed for pressure sensors, including PCF fabrication to introduce birefringence and pressure sensor design incorporating the PCFs. Simulation and experimental results for pressure sensors incorporating two common principles, grating and interferometry, are presented. The flexibility of designing PCF microstructures means PCF pressure sensors with very high sensitivity and accuracy are relatively easily fabricated, compared with conventional methods based on single-mode fibers, microcavities, or electrical methods. Various PCF-based pressure sensor performances are compared. Pressure sensitivity varies with the employed principle, and we show that polarimetric techniques provide the highest sensitivity compared with other types. Higher sensor sensitivity and resolution allows for a large measurement dynamic range. The proposed novel pressure sensors will meet the increasing requirements and have many applications for pressure monitoring, e.g., oil industry and biomedical detection.