Fig. 1. Process of device fabrication: (a) splicing the capillary glass tube (light blue) with the single-mode optical fiber (gray) and cutting it to a predetermined length (∼50 µm); (b) transferring the graphene membrane; (c) covering the air core of the capillary glass tube with UV glue film; (d) riveting the graphene with a ∼100-nm-thick gold film coating via magnetron sputtering; (e) removing the UV glue film and attaching the SPIONs onto the graphene; (f) cutting the integrated SPIONs-graphene sheet in a rectangular shape via a femtosecond laser; (g) optical microscopy image of the SPIONs-integrated magnetic field fiber-tuned GMR encapsulated in a glass tube.

Fig. 2. Characterization of integrated sheet. (a) Raman spectrum of the graphene membrane; (b) SEM image of the graphene membrane; (c) the magnification of (b) to show nanoparticles.

Fig. 3. Optical reflected-interference spectrum of the F-P resonator.

Fig. 4. Schematic of the experimental setup. PC, polarization controller; EOM, electro-optical modulator; EDFA, erbium-doped fiber amplifier; VNA, vector network analyzer; PD, photodetector.

Fig. 5. (a) Resonance frequency spectrum of graphene mechanical resonator; (b) magnetic-field response in the ascending and descending processes. The inset in (b) shows the average value and error bar.