Abstract
This paper describes the design and construction of a magnetostrictive composite-fiber-optic Mach-Zehnder interferometer capable of magnetic field and metal profile measurement. Unlike previous metal detectors, the sensor makes use of the magnetostriction effect on a fiber-optic interferometer to detect metallic objects. The metal detector overcomes many difficulties existing in conventional metal detectors. Aside from offering relatively high sensitivity (sensitivity of about 70.7 × 10 -3 rad/gauss), the optical detection provides resistance to RF interference which is common in typical electromagnetic type metal detectors. The magnetostrictive sensor is also relatively compact and able to achieve a minimum spatial resolution of 1 cm 2 for metal profile detection. © 2014 Springer International Publishing.