A reflective intensity modulated fiber tilt angle sensor based on an all-photonic crystal fiber interferometer

A highly sensitive tilt angle sensor based on an all-photonic crystal fiber interferometer (All-PCFI) was proposed and demonstrated in this paper. The All-PCFI was formed by a PCF with two collapse regions that were fabricated by fusion discharge technique. Then a device formed by cantilever beams and iron ball was designed to transform the tilt angle to the strain, which would be detected by measuring the spectral responses of the All-PCFI. Experimental results showed that the spectrum would be red-shifted when the tilt angle changed from 0° to 90°. And in the measurement range of 0°-45°, the linear measurement sensitivity could be up to 55.67 pm/°. In addition, the sensor could measure the tilt angle in all directions by demodulating signals of the four cantilever beams.