Optical fiber sensor based on Bloch surface wave in photonic crystals.

A new optical fiber sensor based on Bloch surface wave was theoretically proposed. An omnidirectional one-dimensional photonic crystal was designed as the multilayer coated on the outer surface of the optical fiber. Taking advantages of the omnidirectional reflection band, there is only surface mode resonance in the transmission spectrum, while guided mode resonance is avoided. The performance of the designed fiber sensor was analyzed theoretically with a ray transmission model. The presented sensor has comparable sensitivity but much higher figure of merit than other fiber sensors. The resolution can reach about 10 RIU or even higher.