Interrogation of fibre Bragg gratings with a tilted fibre Bragg grating

A new and efficient interrogation scheme suitable for monitoring the Bragg wavelengths of multiplexed fibre Bragg gratings is presented. The heart of the technique consists of a tilted and chirped fibre Bragg grating placed in front of a photodetector linear array. Throughout the paper the principle of operation is discussed and experimentally validated. The technique presents good characteristics such as a worst-case 3.4 pm wavelength resolution, or an interrogation capability for multiplexed sensors.