Fig. 1. Schematic diagram of the sensor.

Fig. 2. Experiment and simulation spectra of the proposed sensor.

Fig. 3. Schematic of the experimental setup for strain measurement.

Fig. 4. Experiment results for a single PMF Sagnac interferometer with (a) the spectrum variation with strain increasing, (b) the spectrum variation with temperature increasing, (c) dip shift with strain variation, and (d) dip shift with temperature variation.

Fig. 5. (a) The experiment spectrum and the envelope of it. (b) The variation of the fitted envelope with increasing strain.

Fig. 6. Relationship between the wavelength and strain for the proposed sensor.

Fig. 7. Relationship between the wavelength and temperature for the proposed sensor.