The advent of multiplexing interferometric schemes for fibre Bragg grating (FBG) sensor interrogation has enabled the combination of large-scale multiplexing and high-resolution measurement. In this letter, we describe a fast and simple technique to add absolute wavelength measurement capabilities to any passive-interferometric multiplexer. Through simulation we demonstrate a wavelength accuracy of <10 pm using common system specifications. The technique allows high-resolution interferometric interrogation to be applied to many key industrial applications requiring precise knowledge of absolute values, such as static temperature, without trading off high interrogation rate or resolution.
- wavelength calibration technique
- grating sensor
- fibre Bragg
- interrogation systems