Photonics Research, 2020, 8 (7): 07001064, Published Online: Jun. 4, 2020
Ultrabroadband and sensitive cavity optomechanical magnetometry Download: 717次
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 ( ) optical microcavity on a silicon chip. By engineering their physical structure, we achieve a peak sensitivity of 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.
Bei-Bei Li, George Brawley, Hamish Greenall, Stefan Forstner, Eoin Sheridan, Halina Rubinsztein-Dunlop, Warwick P. Bowen. Ultrabroadband and sensitive cavity optomechanical magnetometry[J]. Photonics Research, 2020, 8(7): 07001064.