A Portable Smartphone-Based Vector-Magnetometer Illuminated and Imaged via a Side-Polished-Fiber Functionalized With Magnetic Fluid

A new concept for portable vectormagnetometer, based on smartphone platform and sidepolished-fiber (SPF) integrated with magnetic fluid (MF), is proposed and demonstrated. The magnetometer is designed on a smartphone, which incorporates the functions of light source, detector, and data processing together, and is illuminated and imaged via the SPF. Moreover, thanks to the non-central symmetric structure of the SPF and the magnetic-field-induced anisotropic distribution of the MF around the SPF, the proposed magnetometer is able to detect the intensity and the orientation of magnetic field simultaneously. Experimental results show that the sensitivities of the proposed magnetometer to magnetic field intensity and orientation can reach -0.050 dB/Oe and -0.263 dB/degree, corresponding to the measurement resolutions of 0.336 Oe and 0.064 degree respectively, which are comparable to or even better than that obtained by the traditional platform. Our design can avoid the use of complex and expensive instruments that are employed in the traditional platform. Because of the features of portability, low cost, and highly-sensitive vector measurement, etc., the proposed magnetometer is advantageous for the applications in sensing magnetic vector requiring a portable size and real-time transmission of the measured results.