Invited Article: Scalable high-sensitivity optomechanical magnetometers on a chip
Abstract
The dual-resonant enhancement of mechanical and optical response in cavity optomechanical magnetometers enables precision sensing of magnetic fields. In previous working prototypes of such magnetometers, a cavity optomechanical system is functionalized by manually epoxy-bonding a grain of magnetostrictive material. While this approach allows proof-of-principle demonstrations, practical applications require more scalable and reproducible fabrication pathways. In this work, we developed a multiple-step method to scalably fabricate optomechanical magnetometers on a silicon chip, with reproducible performance across different devices. The key step is to develop a process to sputter coat a magnetostrictive film onto high quality toroidal microresonators, without degradation of the optical quality factor. A peak sensitivity of 585 pT/Hz is achieved, which is comparable with previously reported results using epoxy-bonding. Furthermore, we demonstrate that thermally annealing the sputtered film can improve the magnetometer sensitivity by a factor of 6.3.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 01, 2018
- Source ID
- 10.1063/1.5055029
Entities
People
- Ali Dehghan-manshadi
- Bei-Bei Li
- Douglas Bulla
- Halina Rubinsztein-Dunlop
- Scott Foster
- Stefan Forstner
- Varun Prakash
- Warwick P. Bowen
Organizations
- Australian Research Council
- Defence Science and Technology Group
- Defense Advanced Research Projects Agency
- University of Queensland