Ultrabroadband and sensitive cavity optomechanical magnetometry
Abstract
Magnetostrictive optomechanical cavities provide a new optical readout approach to room-temperature magnetometry. Here we report ultrasensitive and ultrahigh bandwidth cavity optomechanical magnetometers constructed by embedding a grain of the magnetostrictive material Terfenol-D within a high quality ( Q ) optical microcavity on a silicon chip. By engineering their physical structure, we achieve a peak sensitivity of 26 pT / Hz comparable to the best cryogenic microscale magnetometers, along with a 3 dB bandwidth as high as 11.3 MHz. Two classes of magnetic response are observed, which we postulate arise from the crystallinity of the Terfenol-D. This allows single crystalline and polycrystalline grains to be distinguished at the level of a single particle. Our results may enable applications such as lab-on-chip nuclear magnetic spectroscopy and magnetic navigation.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 03, 2020
- Source ID
- 10.1364/prj.390261
Entities
People
- Bei-Bei Li
- Eoin Sheridan
- George Brawley
- Halina Rubinsztein-Dunlop
- Hamish Greenall
- Stefan Forstner
- Warwick P. Bowen
Organizations
- Australian Research Council
- Defence Science and Technology Group
- Defense Advanced Research Projects Agency
- University of Queensland