On-Chip Magnetometer

This innovation is a Photonic Integrated Circuit (PIC)-based magnetometer that can be used to measure nano- and sub-nano-tesla magnetic fields. High-sensitivity magneto optic nanocomposite materials are used as optical device cladding and/or device materials to register a shift in light polarization due to Faraday rotation. Devices based on evanescent field interaction may include ring/disc/whispering-gallery resonators, on-chip adiabatic tapers, or low-index contrast waveguide/clad configurations. Devices based on nanocomposite waveguides/devices may be fabricated directly from patterned nanocomposite films. Differential detection techniques can also be employed to achieve sub-micro-Tesla level detection. 

Background:    
Using differential detection and evanescent fields that interact with magneto-optic materials on a photonic chip, magnetic fields can be measured well below both the limitations of the surrounding Earth’s magnetic field and other urban magnetic fields. These devices use on-chip resonators and tapered fibers with magneto-optic nanocomposite polymers as a top cladding material. The Faraday effect is then used to determine the strength and orientation of the present field via measurements of the changes in the light polarization state. A magneto-optic magnetometer by way of on-chip resonators or tampered waveguides can be used in domestic, military, and biomedical fields for measuring magnetic fields. Atomic vapor magnetometers, MRI imaging, SQUID sensors, and general magnetometers are currently the leading competition for highly sensitive magnetometers. 

Applications: 

• Military magnetic field measuring 
• Medical magnetic field measuring
• Domestic magnetic field measuring

Advantages: 

• On-chip (compact, low consumption, transportable, versatile)
• Capable of measuring nano-Tesla and sub-nano-Tesla magnetic fields