Low frequency on-chip magnetometry using optical microcavities

Speaker: Hamish Greenall
Affiliation: University of Queensland

Abstract

Magnetometers have many applications including magnetic anomaly detection, geophysical mapping, magnetic resonance imaging and more. The current state-of-the-art commercially available magnetometers, superconducting quantum interference device (SQUID) magnetometers, require a cryogenic environment to operate; as such they are expensive, bulky and power hungry. In our lab, we have created microtoroidal cavity optomechanical magnetometers operating in the MHz frequency range, which have achieved state-of-the-art sensitivities comparable to SQUIDS using only microwatt power consumption and without the need for cryogenics. These however fail at low frequencies, where many applications operate. In my PhD I am engineering new forms of cavity optomechanical magnetometers that are capable of high sensitivity at low frequencies, using microresonators with hybridised optical modes. In my talk I will discuss their predicted performance, the results from devices fabricated thus far and my plans to demonstrate their use in applications, such as kHz frequency communications and deployment on a UAV.