Simple fiber optic device to interrogate fiber optic Bragg gratings used as sensors

A simple and compact device for the monitoring and diagnostic of fiber optic Bragg gratings, employed in optical sensor applications, was developed. The deice consist of an optical fiber Bragg grating bound to a piezoelectric element. When a sinusoidal voltage is applied to the piezoelectric, the Bragg wavelength of the grating changes and the transmission spectrum swings in time. The device acts as a temporal window and can be used to interrogate a Bragg grating sensor, permitting to monitor the sensor state in real time and with very good resolution.