Multichannel fiber-optic magnetometer system for undersea measurements

A Review of Recent Developments in Fiber Optic Sensor Technology

“…This magnetic array system (MARS) [68] was a joint US/Norway program to test the feasibility of using fiber optic-based magnetic field sensors for long-term environmental (geomagnetic) and marine traffic monitoring. This system, which comprised eight nodes of 3-axis magnetometers, used metallic glass (Metlas) strip transducers which were bonded to a multiple loop fiber coil.…”

Directivity of the Magnetostrictive Fiber-Optic Interferometric Transducers

“…In magnetostrictive fiber-optic interferometric sensors, the phase shift is proportional to the square of the applied magnetic field [8] and can be expressed as…”

“…So far, four typical kinds of transducers have been proposed [2], [5], [6], and it has been proved that the cylindrical transducer has the best magnetic-field response due to its effective stress transmission from magnetostrictive material to the fiber [7]. Practical applications generally require the detection of both the field amplitude and its direction, and a vector magnetometer had to be constructed to form sensor arrays [8]. Therefore, in addition to the sensitivity, the directivity of the sensors is also important in the transducer design.…”

All-optical, Three-axis Fiber Laser Magnetometer

“…Such a technique is known as moving target detection (MTD). In this configuration, analysis of data from multiple spatially dispersed sensing units enables remote referencing [1] to remove the drift due to temporal variation in the Earth's field as well as target tracking [2]. Such systems are suited to coastline or harbor monitoring and are the target applications for the current system.…”

“…The photovoltaic converter, known as a photonic power converter (PPC), 2 consists of a planar array of photodiodes connected in series and operated in a photovoltaic mode. This enables high current generation into a low impedance load.…”