In this paper,we propose a deformed Reuleaux-triangle resonator(RTR)to form exceptional point(EP)which results in the detection sensitivity enhancement of nanoparticle.After introducing single nanoparticle to the deformed RTR at EP,frequency splitting obtains an enhancement of more than 6 times compared with non-deformed RTR.In addition,EP induced a result that the far feld pattern of chiral mode responses signifcantly to external perturbation,corresponding to the change in internal chirality.Therefore,single nanoparticle with far distance of more than 4000 nm can be detected by measuring the variation of far feld directional emission.Compared to traditional frequency splitting,the far feld pattern produced in deformed RTR provides a cost-efective and convenient path to detect single nanoparticle at a long distance,without using tunable laser and external coupler.Our structure indicates great potential in high sensitivity sensor and label-free detector.
Jinhao FeiXiaobei ZhangQi ZhangYong YangZijie WangChuanlu DengYi HuangTingyun Wang
Dynamic monitoring of blood pressure (BP) is beneficial to obtain comprehensive cardiovascular information of patients throughout the day. However, the clinical BP measurement method relies on wearing a bulky cuff, which limits the long-term monitoring and control of BP. In this work, a microcavity assisted graphene pressure sensor (MAGPS) for single-vessel local BP monitoring is designed to replace the cuff. The microcavity structure increases the working range of the sensor by gas pressure buffering. Therefore, the MAGPS achieves a wide linear response of 0–1050 kPa and sensitivity of 15.4 kPa^(−1). The large working range and the microcavity structure enable the sensor to fully meet the requirements of BP detection at the radial artery. A database of 228 BP data (60-s data fragment detected by MAGPS) and 11,804 pulse waves from 9 healthy subjects and 5 hypertensive subjects is built. Finally, the BP was detected and analyzed automatically by combining MAGPS and a two-stage convolutional neural network algorithm. For the BP detection method at local radial artery, the first stage algorithm first determines whether the subject has hypertension by the pulse wave. Then, the second stage algorithm can diagnose systolic and diastolic BP with the accuracy of 93.5% and 97.8% within a 10 mmHg error, respectively. This work demonstrates a new BP detection method based on single vessel, which greatly promotes the efficiency of BP detection.
Microcavity photon dynamics in curved space is an emerging interesting area at the crossing point of nanophotonics,chaotic science,and non-Euclidean geometry.We report the sharp difference between the regular and chaotic motions of cavity photons subjected to the varying space curvature.While the island modes of regular motion rise in the phase diagram in the curved space,the chaotic modes show special mechanisms to adapt to the space curvature,including the fast diffusion of ray dynamics,and the localization and hybridization of the Husimi wavepackets among different periodic orbits.These observations are unique effects enabled by the combination of the chaotic trajectory,the wave nature of light,and the non-Euclidean orbital motion,and therefore make the system a versatile optical simulator for chaotic science under quantum mechanics in curved space-time.
Wei LinYechun DingYongsheng WangPeng LiYanpeng ZhangFeng YunFeng Li
This study investigates the properties of exciton-polaritons in a two-dimensional(2D)hybrid organic-inorganic perovskite microcavity in the presence of optical Stark effect.Through both steady and dynamic state analyses,strong coupling between excitons of perovskite and cavity photons is revealed,indicating the formation of polaritons in the perovskite microcavity.Besides,it is found that an external optical Stark pulse can induce energy shifts of excitons proportional to the pulse intensity,which modifies the dispersion characteristics of the polaritons.
Kenneth Coker郑楚媛Joseph Roger ArhinKwame Opuni-Boachie Obour Agyekum张伟利
Cavity optomechanical systems have enabled precision sensing of magnetic fields,by leveraging the optical resonance-enhanced readout and mechanical resonance-enhanced response.Previous studies have successfully achieved mass-produced and reproducible microcavity optomechanical magnetometry(MCOM)by incorporating Terfenol-D thin films into high-quality(Q)factor whispering gallery mode(WGM)microcavities.However,the sensitivity was limited to 585 pT Hz^(−1/2),over 20 times inferior to those using Terfenol-D particles.In this work,we propose and demonstrate a high-sensitivity and mass-produced MCOM approach by sputtering a FeGaB thin film onto a high-Q SiO2 WGM microdisk.Theoretical studies are conducted to explore the magnetic actuation constant and noise-limited sensitivity by varying the parameters of the FeGaB film and SiO2 microdisk.Multiple magnetometers with different radii are fabricated and characterized.By utilizing a microdisk with a radius of 355μm and a thickness of 1μm,along with a FeGaB film with a radius of 330μm and a thickness of 1.3μm,we have achieved a remarkable peak sensitivity of 1.68 pT Hz^(−1/2)at 9.52 MHz.This represents a significant improvement of over two orders of magnitude compared with previous studies employing sputtered Terfenol-D film.Notably,the magnetometer operates without a bias magnetic field,thanks to the remarkable soft magnetic properties of the FeGaB film.Furthermore,as a proof of concept,we have demonstrated the real-time measurement of a pulsed magnetic field simulating the corona current in a high-voltage transmission line using our developed magnetometer.These high-sensitivity magnetometers hold great potential for various applications,such as magnetic induction tomography and corona current monitoring.
