We have used a gold nanohole array to trap single polystyrene nanoparticles, with a mean diameter of 30 nm, into separated hot spots located at connecting nanoslot regions. A high trap stiffness of approximately 0.85...We have used a gold nanohole array to trap single polystyrene nanoparticles, with a mean diameter of 30 nm, into separated hot spots located at connecting nanoslot regions. A high trap stiffness of approximately 0.85 fN∕(nm·m W)at a low-incident laser intensity of ～0.51 m W∕μm^2 at 980 nm was obtained. The experimental results were compared to the simulated trapping force, and a reasonable match was achieved. This plasmonic array is useful for lab-on-a-chip applications and has particular appeal for trapping multiple nanoparticles with predefined separations or arranged in patterns in order to study interactions between them.展开更多
Tapered fibers with diameters ranging from 1 to 4 μm are widely used to excite the whispering-gallery(WG)modes of microcavities. Typically, the transmission spectrum of a WG cavity coupled to a waveguide around a res...Tapered fibers with diameters ranging from 1 to 4 μm are widely used to excite the whispering-gallery(WG)modes of microcavities. Typically, the transmission spectrum of a WG cavity coupled to a waveguide around a resonance assumes a Lorentzian dip morphology due to resonant absorption of the light within the cavity. In this paper, we demonstrate that the transmission spectra of a WG cavity coupled with an ultrathin fiber(500–700 nm)may exhibit both Lorentzian dips and peaks, depending on the gap between the fiber and the microcavity. By considering the large scattering loss of off-resonant light from the fiber within the coupling region, this phenomenon can be attributed to partially resonant light bypassing the lossy scattering region via WG modes, allowing it to be coupled both to and from the cavity, then manifesting as Lorentzian peaks within the transmission spectra.This implies the system could be implemented within a bandpass filter framework.展开更多
In this work, a hybrid structure consisting of a multicomponent germanate glass microsphere containing bismuth as a gain medium is proposed and presented. The bismuth-doped germanate glass microspheres were fabricated...In this work, a hybrid structure consisting of a multicomponent germanate glass microsphere containing bismuth as a gain medium is proposed and presented. The bismuth-doped germanate glass microspheres were fabricated from a glass fiber tip with no precipitation of the bismuth metal. Coupling with a fiber taper, the bismuth-doped microsphere single-mode laser was observed to lase at around 1305.8 nm using 808 nm excitation. The low threshold of absorbed pump power at 215 μW makes this microlaser appealing for various applications, including tunable lasers for a range of purposes in telecommunication, biomedical, and optical information processing.展开更多
基金Okinawa Institute of Science and Technology Graduate University
文摘We have used a gold nanohole array to trap single polystyrene nanoparticles, with a mean diameter of 30 nm, into separated hot spots located at connecting nanoslot regions. A high trap stiffness of approximately 0.85 fN∕(nm·m W)at a low-incident laser intensity of ～0.51 m W∕μm^2 at 980 nm was obtained. The experimental results were compared to the simulated trapping force, and a reasonable match was achieved. This plasmonic array is useful for lab-on-a-chip applications and has particular appeal for trapping multiple nanoparticles with predefined separations or arranged in patterns in order to study interactions between them.
基金Okinawa Institute of Science and Technology Graduate University(OIST)
文摘Tapered fibers with diameters ranging from 1 to 4 μm are widely used to excite the whispering-gallery(WG)modes of microcavities. Typically, the transmission spectrum of a WG cavity coupled to a waveguide around a resonance assumes a Lorentzian dip morphology due to resonant absorption of the light within the cavity. In this paper, we demonstrate that the transmission spectra of a WG cavity coupled with an ultrathin fiber(500–700 nm)may exhibit both Lorentzian dips and peaks, depending on the gap between the fiber and the microcavity. By considering the large scattering loss of off-resonant light from the fiber within the coupling region, this phenomenon can be attributed to partially resonant light bypassing the lossy scattering region via WG modes, allowing it to be coupled both to and from the cavity, then manifesting as Lorentzian peaks within the transmission spectra.This implies the system could be implemented within a bandpass filter framework.
基金National Natural Science Foundation of China(NSFC)(61575050)Key Program for International S&T Cooperation Projects of China(2016YFE0126500)+3 种基金Key Program for Natural Science Foundation of Heilongjiang Province of China(ZD2016012)111 Project(B13015)Fundamental Research Funds of the Central UniversityHarbin Engineering University(HEU)
文摘In this work, a hybrid structure consisting of a multicomponent germanate glass microsphere containing bismuth as a gain medium is proposed and presented. The bismuth-doped germanate glass microspheres were fabricated from a glass fiber tip with no precipitation of the bismuth metal. Coupling with a fiber taper, the bismuth-doped microsphere single-mode laser was observed to lase at around 1305.8 nm using 808 nm excitation. The low threshold of absorbed pump power at 215 μW makes this microlaser appealing for various applications, including tunable lasers for a range of purposes in telecommunication, biomedical, and optical information processing.
