报告题目：Hybrid diamond-glass optical fibre for magnetic sensing
报告人：Dr. Dongbi Bai
主持人：李文雪教授
时间：7月27日（周五）上午10:00
地点：理科大楼A814会议室
主办单位：精密光谱科学与技术国家重点实验室
报告摘要：
We demonstrate a new type of hybrid diamond-glass fibre with potential applications as a field-deployable fibre sensing system. The fibre was fabricated using the rod-in-tube technique and a lead silicate glass with refractive index of 1.62 at 656 nm wavelength. The thin glass rod of ~1 mm diameter was coated with nitrogen-vacancy (NV) centres doped diamond microparticles of ~1 μm diameter, inserted into the glass tube, and this rod-in-tube assembly was drawn down to fibre of ~160 μm diameter, with the diamond particles being distributed at the fused interface. We experimentally examined the photoluminescence (PL) and magnetic-sensing properties of the diamond-glass optical fibre by using confocal microscopy setup.With 532-nm continuous-wave excitation, the embedded diamond particles presented strong PL intensities of NV centres. Simultaneously, a clear PL dip at ~2.87 GHz was observed in the optically detected magnetic resonance (ODMR) spectrum with applied microwave radiation. These results confirm the NV centres were well-preserved during fibre fabrication process. The Zeeman frequency shifts of embedded NV centres were further employed as an indicator of external magnetic fields. The diamond-glass optical fibre sensor demonstrated a room-temperature, shot noise-limited DC magnetic field sensitivity of 350 nT/Hz, which is approximately two orders of magnitude greater than previous results derived from nanodiamond-doped tellurite fibre. The initial results suggest that the coupling of fluorescence from NV centres to guided modes of a conventional step-index optical fibre will be possible, opening the realisation of a compact, high-efficiency fibre platform for remote magnetometry by using diamond-glass hybrid materials.
报告人简介
Dongbi Bai
Dongbi Bai received her B.S. in Dept. of Physics, East China Normal University in 2011, and PhD degree in Optics in State Key Laboratory of Precision Spectroscopy, East China Normal University in 2016. During her PhD period, she worked on the development of novel fibre laser oscillator, amplifier, and the precise noise-suppression of fibre-based optical frequency comb systems. She currently works as a research fellow in School of Science, Royal Melbourne Institute of Technology (RMIT University) in Australia. Participating in an Australian Defence Science and Technology Group (DST) funded Competitive Evaluation Research Agreement (CERA) program, her current research interests include optical fibre fabrication, fluorescent nanoparticles characterisation, and remote diamond-magnetometry.