Dual FFPI Strain Sensor with Low-Cost LED Light Source

Abstract

Seeking an accurate, reliable, highly sensitive, and low-cost detector is always an exciting challenge for sensor researchers. Here, a dual fiber-optic Fabry-Perot interferometer (FFPI) for strain sensors with a low-cost communication light-emitting diode (LED) replacing expensive laser diode was experimentally implemented. Both an expensive light source and costly Faraday isolator were waived in this system. The dynamic strain modulation in the sensing FFPI was with a piezoelectric transducer (PZT). The characteristic performance showing both modulation and detection is almost identical. The temperature variation in the sensing part was simultaneously detected with demodulation of a reference FFPI.