Electro-optical magnetic microsensor with reducing interference packaging

A novel electro-optical magnetic microsensor with reducing interference packaging mechanism for sensing magnetic field strength was demonstrated. Both capacitive and optical fiber sensing microstructures surrounded magnetic shields were fabricated in a chip using low temperature silicon-based micro-electro-mechanical systems (MEMS) compatible technology. Varied NiFe permalloy flaps embedded on polyimide membranes were used as flexible sensing mechanisms to actuate side-polished fiber and capacitor plate. The fiber Bragg gratings (FBGs) were used as optical sensors with high sensitivity. Results of simulations and experiments show that the structures can reduce interference and then increase sensitivity and performance effectively. A sensitivity of 1.32 nm/T is achieved by evaluating the peak shift of wavelength excited by Nd-Fe-B magnets with residual magnetic strength up to 1.12 T.