Brady, G.P., Kalli, K., Webb, D.J., Jackson, D.A., Reekie, L. and Archambault, J.L.
Simultaneous interrogation of interferometric and Bragg grating sensors.
Optics Letters, 20, (11), . (doi:10.1364/OL.20.001340).
We propose a new method for the simultaneous interrogation of conventional two-beam interferometers and Bragg grating sensors. The technique employs an unbalanced Mach-Zehnder interferometer illuminated by a single lowcoherence source, which acts as a wavelength-tunable source for the grating and as a path-matched filter for the Fizeau interferometer, thus providing a high phase resolution output for each sensor. The grating sensor demonstrates a dynamic strain resolution of ~0.05 ??/?Hz at 20 Hz, while the interferometric phase resolution is better than 1 mrad/?Hz at 20 Hz, corresponding to an rms mirror displacement of 0.08 nm.
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