Avoided-crossing-based ultrasensitive photonic crystal fiber refractive index sensor.
We propose and demonstrate an ultrasensitive photonic crystal fiber refractive index sensor by introducing the avoided-crossing effect in a bent-controlled fluid-filled photonic-bandgap fiber (FF-PBGF). By controlling the bend radius of the FF-PBGF, resonant couplings between the fundamental core mode and the cladding modes are realized and transmission notches are observed in the transmission band of the FF-PBGF. By changing the refractive index or temperature of the bent FF-PBGF, a sensitivity of 32,400 nm per refractive index unit (or 13.1 nm/degrees C) is achieved, which is the highest for a fiber device to date, to our best knowledge.
Han
Tingting
T
Key laboratory of Opto-electronic Information and Technology, Ministry of Education and Institute of Modern Optics, Nankai University, Tianjin 300071, China.
Liu
Yan-ge
YG
Wang
Zhi
Z
Zou
Bing
B
Tai
Boyin
B
Liu
Bo
B