Zero-power magnetometers with remote optical interrogation

A magnetic-field-sensing system that consists of a miniature zero-power magnetometer, an integrated micromachined corner-cube reflector (CCR), commercially available diode laser, and a photo-detector array, has been designed, fabricated, assembled, and tested. The sensor node occupies a volume of only 1.5 mm³ and can detect a magnetic field between 0 to 6 kA/m. The primary application of this technology is in wireless sensing systems that must operate continuously without providing or maintaining the sensor-node energy (e.g., replacing batteries or scavenging energy) or in extremely harsh environments.