Response to pressure of a hollow core photonic crystal fiber for sensing applications

The response to pressure of a hollow core photonic crystal fiber is investigated. The fiber is designed to operate at 1550 nm but presents core-guided transmission windows in the visible spectral range that have shown to be highly dependent on the exact fiber structure. As the fiber is submitted to pressure, small structural and index changes, thus, affect these windows. The fiber response depends on whether pressure is applied internally or externally and pressure sensitivity can be of units of kgf/cm² up to hundreds of kgf/cm². In addition, it was found that the fiber presents a birefringence which is also pressure dependent. These characteristics can be exploited for the development of pressure sensors based on intensity or polarization modulation.