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A microfabricated fiber-integrated diamond magnetometer with ensemble nitrogen-vacancy centers

MetadataDetails
Publication Date2022-05-09
JournalApplied Physics Letters
AuthorsFei Xie, Yuqiang Hu, Lingyun Li, Cao Wang, Qihui Liu
InstitutionsState Key Laboratory of Transducer Technology, Shanghai University
Citations30

Miniaturization is a trend of development toward practical applications for diamond nitrogen-vacancy centers-based sensors. We demonstrate a compact diamond magnetic field sensor device using a standard microfabrication process. A single-crystal-diamond plate is embedded in a cavity formed with stacking of three silicon chips. Thermal compression bonding is implemented at silicon-silicon and diamond-silicon interfaces ensuring mechanical robustness. The specific construction volume for the essential sensor component is about 10 Ɨ 10 Ɨ 1.5 mm3. By integrating a gradient index lens pigtailed fiber to the sensor device, 532-nm laser light and emitted fluorescence share a common path for excitation and detection. An omega-shaped transmission line for applied microwave power is fabricated directly on the surface of diamond. The integrated sensor device exhibits an optimized sensitivity of 2.03 nTĀ·Hzāˆ’1/2 and over twofold enhancement of fluorescence collection efficiency compared to bare diamond. Such a sensor is utilized to measure a magnetic field change caused by switching a household electrical appliance.