Tunable filter interrogation method with a modulated fiber Bragg grating

This work describes the use of a mechanically modulated fiber Bragg grating to address a single fiber Bragg grating sensor using the tunable filter method. A special mechanical apparatus driven by a small PZT device is devised and fabricated to implement the tunability of the interrogating element which is another fiber Bragg grating that can be modulated and stretched to scan the spectral range of operation of the sensor.