Fiber Bragg Grating and Magnetic Shape Memory Alloy: Novel High-Sensitivity Magnetic Sensor

A magnetic field sensor based on the integration of a fiber Bragg grating (FBG) with a magnetic shape memory alloy (MSMA) is demonstrated. MSMA is a new kind of material able to show extremely large strains in response to a magnetic field. Moreover, differently from classical shape memory alloys, which are actuated by temperature, MSMAs normally show quite fast responses. In this brief, the basic features of the proposed device are illustrated, and field range and sensitivity of the device are also discussed. Moreover, comparison with Terfenol-based FBG sensor performances is reported showing results with a sensitivity (DeltalambdaB/lambda
_B
)/(DeltaH/H
_m
) of 1.81middot10
^-4
, where lambda
_B
is the Bragg wavelength and H
_m
the mean magnetic field in the considered range