Magnetic field imager with optically pumped magnetmeter and its applications

We have developed an AC magnetic field imaging system by combining an optically pumped magnetometer and a digital micromirror device. This system has been demonstrated to acquire distribution images representing the magnetic field generated by an electric current. We are investigating the application of this system to magnetic particle imaging for use in diagnostic applications. Particle signal generation requires an AC excitation field. Both the excitation field and the signal field from the particles are detected by the optically pumped magnetometer. They are analyzed using phase-sensitive detection with a lock-in amplifier. The resulting field images provides a clear indication of the positions of the particles.