As miniature fibre-optic platforms,micro/nanofibres(MNFs)taper-drawn from silica fibres have been widely studied for applications from optical sensing,nonlinear optics to optomechanics and atom optics.While continuous...As miniature fibre-optic platforms,micro/nanofibres(MNFs)taper-drawn from silica fibres have been widely studied for applications from optical sensing,nonlinear optics to optomechanics and atom optics.While continuous-wave(CW)optical waveguiding is frequently adopted,so far almost all MNFs are operated in low-power region(e.g.,<0.1 W).Here,we demonstrate high-power low-loss CW optical waveguiding in MNFs around 1550-nm wavelength.We show that a pristine MNF,even with a diameter down to 410 nm,can waveguide an optical power higher than 10 W,which is about 30 times higher than demonstrated previously.Also,we predict an optical damage threshold of 70 W.In highpower CW waveguiding MNFs,we demonstrate high-speed optomechanical driving of microparticles in air,and second harmonic generation efficiency higher than those pumped by short pulses.Our results may pave a way towards high-power MNF optics,for both scientific research and technological applications.展开更多
The ability to sense heat and touch is essential for healthcare,robotics,and human–machine interfaces.By taking advantage of the engineerable waveguiding properties,we design and fabricate a flexible optical microfib...The ability to sense heat and touch is essential for healthcare,robotics,and human–machine interfaces.By taking advantage of the engineerable waveguiding properties,we design and fabricate a flexible optical microfiber sensor for simultaneous temperature and pressure measurement based on theoretical calculation.The sensor exhibits a high temperature sensitivity of 1.2 nm/℃ by measuring the shift of a high-order mode cutoff wavelength in the short-wavelength range.In the case of pressure sensing,the sensor shows a sensitivity of 4.5%per kilopascal with a fast temporal frequency response of 1000 Hz owing to the strong evanescent wave guided outside the microfiber.The cross talk is negligible because the temperature and pressure signals are measured at different wavelengths based on different mechanisms.The properties of fast temporal response,high temperature,and pressure sensitivity enable the sensor for real-time skin temperature and wrist pulse measurements,which is critical to the accurate analysis of pulse waveforms.We believe the sensor will have great potential in wearable optical devices ranging from healthcare to humanoid robots.展开更多
We theoretically investigate dark dimer mode excitation and strong coupling with a nanorod dipole. Efficient excitation of a dark mode in a gold(Au) nanorod dimer using an electric dipole can be achieved by an optimal...We theoretically investigate dark dimer mode excitation and strong coupling with a nanorod dipole. Efficient excitation of a dark mode in a gold(Au) nanorod dimer using an electric dipole can be achieved by an optimal overlap between the dipole moment and dark modal field. By replacing the dipole emitter with an Au nanorod, a plane wave excited dipole mode in the nanorod can be effectively coupled to the dark dimer mode through nearfield interaction. At a 10-nm separation of the nanorod and the dimer, plasmonic interaction between dipole-dark modes enters the strong coupling regime with a Rabi-like splitting of 219.2 meV, which is further evidenced by the anticrossing feature and Rabi-like oscillation of electromagnetic energy of the coupled modes. Our results propose an efficient approach to far-field activating dark modes in coupled nanorod dimers and exchanging plasmonic excitations at nanoscale, which may open new opportunities for nanoplasmonic applications such as nanolasers or nanosensors.展开更多
基金supported by the National Key Research and Development Project of China(2018YFB2200404)the National Natural Science Foundation of China(62175213,62175122,and 92150302)+1 种基金the Zhejiang Provincial Natural Science Foundation of China(LR21F050002)the Fundamental Research Funds for the Central Universities.
文摘As miniature fibre-optic platforms,micro/nanofibres(MNFs)taper-drawn from silica fibres have been widely studied for applications from optical sensing,nonlinear optics to optomechanics and atom optics.While continuous-wave(CW)optical waveguiding is frequently adopted,so far almost all MNFs are operated in low-power region(e.g.,<0.1 W).Here,we demonstrate high-power low-loss CW optical waveguiding in MNFs around 1550-nm wavelength.We show that a pristine MNF,even with a diameter down to 410 nm,can waveguide an optical power higher than 10 W,which is about 30 times higher than demonstrated previously.Also,we predict an optical damage threshold of 70 W.In highpower CW waveguiding MNFs,we demonstrate high-speed optomechanical driving of microparticles in air,and second harmonic generation efficiency higher than those pumped by short pulses.Our results may pave a way towards high-power MNF optics,for both scientific research and technological applications.
基金National Key Research and Development Program of China(2018YFB2200400)National Natural Science Foundation of China(61975173,62075192)+2 种基金Natural Science Foundation of Zhejiang Province(LQ21F050001,LQ22F050021)Major Scientific Research Project of Zhejiang Lab(2019MC0AD01)Key Research and Development Project of Zhejiang Province(2021C05003)。
文摘The ability to sense heat and touch is essential for healthcare,robotics,and human–machine interfaces.By taking advantage of the engineerable waveguiding properties,we design and fabricate a flexible optical microfiber sensor for simultaneous temperature and pressure measurement based on theoretical calculation.The sensor exhibits a high temperature sensitivity of 1.2 nm/℃ by measuring the shift of a high-order mode cutoff wavelength in the short-wavelength range.In the case of pressure sensing,the sensor shows a sensitivity of 4.5%per kilopascal with a fast temporal frequency response of 1000 Hz owing to the strong evanescent wave guided outside the microfiber.The cross talk is negligible because the temperature and pressure signals are measured at different wavelengths based on different mechanisms.The properties of fast temporal response,high temperature,and pressure sensitivity enable the sensor for real-time skin temperature and wrist pulse measurements,which is critical to the accurate analysis of pulse waveforms.We believe the sensor will have great potential in wearable optical devices ranging from healthcare to humanoid robots.
基金National Natural Science Foundation of China(NSFC)(11527901,61475136,61635009)FundamentalResearch Funds for the Central UniversitiesChina Postdoctoral Science Foundation(2018M632454,BX201700207)
文摘We theoretically investigate dark dimer mode excitation and strong coupling with a nanorod dipole. Efficient excitation of a dark mode in a gold(Au) nanorod dimer using an electric dipole can be achieved by an optimal overlap between the dipole moment and dark modal field. By replacing the dipole emitter with an Au nanorod, a plane wave excited dipole mode in the nanorod can be effectively coupled to the dark dimer mode through nearfield interaction. At a 10-nm separation of the nanorod and the dimer, plasmonic interaction between dipole-dark modes enters the strong coupling regime with a Rabi-like splitting of 219.2 meV, which is further evidenced by the anticrossing feature and Rabi-like oscillation of electromagnetic energy of the coupled modes. Our results propose an efficient approach to far-field activating dark modes in coupled nanorod dimers and exchanging plasmonic excitations at nanoscale, which may open new opportunities for nanoplasmonic applications such as nanolasers or nanosensors.