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- 摘要
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- 实验方案
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A hybrid distributed optical fibre sensor for acoustic and temperature fields reconstruction
摘要： We have proposed and experimentally demonstrated a distributed optical fibre sensor (DOFS) based on the hybrid of phase-sensitive optical time domain reflectometry (Ф-OTDR) and Raman optical time domain reflectometry (ROTDR), which could reconstruct the acoustic and temperature fields all along the sensing fibre at the same time. The Rayleigh back scattering (RBS), Raman Stokes (RS) and Raman anti-Stokes (RAS) generated by the probe pulse were separated by a WDM filter. Then the RBS was received by a heterodyne balanced photo detector (BPD) for quantitative vibration measurement and the dynamic acoustic field reconstruction, while the RS and RAS components were received directly by avalanche photodiodes (APDs) for temperature demodulation. The experimental results have shown that the proposed hybrid system could measure the temperature profile along a 12km long standard single-mode fibre with a maximal temperature uncertainty of 0.95℃ and a linearity response of R2=0.9986, along with a periodical knocking event detected simultaneously. Meanwhile, a 100Hz sinusoidal vibration at 12km distance along the same fibre could be clearly identified. Distributed knocking vibration and temperature was achieved at the same time with high accuracy.
关键词： temperature field,Distributed optical fibre sensors,acoustic field,Phase-sensitive OTDR (Ф-OTDR),Raman
更新于2025-09-23 15:21:01
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Acoustic wave transparency in nitrogen-vacancy centers in a photonic crystal
摘要： We show that the interaction of nitrogen-vacancy centers in diamond with a strain field in a photonic crystal can lead to acoustic wave transparency. This occurs due to the strong interaction of photons with the modified photonic reservoir near the photonic band edge created by the photonic crystal. For achieving this, we explore the properties of the spin states of the ground state of the nitrogen-vacancy centers, where one transition interacts with a strain field while the other transition has spontaneous emission that occurs near the edge of the photonic band gap, which should be in the microwave regime. We show that depending on the form of the photonic density of states acoustic wave transparency is obtained at one or two frequencies.
关键词： Induced transparency,Photonic crystal,Non-Markovian dynamics,Acoustic field,Nitrogen-vacancy center in diamond
更新于2025-09-19 17:15:36