The direct interfacing of photonic crystal fiber to a metallic nanoantenna has widespread application in nanoscale imaging, optical lithography, nanoscale lasers, quantum communication, in vivo sensing, and medical su...The direct interfacing of photonic crystal fiber to a metallic nanoantenna has widespread application in nanoscale imaging, optical lithography, nanoscale lasers, quantum communication, in vivo sensing, and medical surgery.We report on the fabrication of a needle-shaped plasmonic nanoantenna on the end facet of a photonic crystal fiber using electron-beam-induced evaporation of platinum. We demonstrate the coupling of light from the fiber waveguide mode to the subwavelength nanoantenna plasmonic mode focusing down to the apex of the plasmonic needle using a polarization-resolved far-field side-scatter imaging technique. Our work provides an important step toward widespread application of optical fibers in nearfield spectroscopic techniques such as tip-enhanced Raman and fluorescence microscopy, single-photon excitation and quantum sensors, nanoscale optical lithography, and lab-on-fiber devices.展开更多
Two-dimensional materials are generating great interest due to their unique electrical and optical properties.In particular, transition metal dichalcogenides such as molybdenum disulfide(MoS_2) are attractive material...Two-dimensional materials are generating great interest due to their unique electrical and optical properties.In particular, transition metal dichalcogenides such as molybdenum disulfide(MoS_2) are attractive materials due to the existence of a direct band gap in the monolayer limit that can be used to enhance nonlinear optical phenomena, such as Raman spectroscopy. Here, we have investigated four-wave mixing processes in bulk MoS_2 using a multiplex coherent anti-Stokes Raman spectroscopy setup. The observed four-wave mixing signal has a resonance at approximately 680 nm, corresponding to the energy of the A excitonic transition of MoS_2. This resonance can be attributed to the increased third-order nonlinear susceptibility at wavelengths near the excitonic transition. This phenomenon could open the path to using MoS_2 as a substrate for enhancing four-wave mixing processes such as coherent anti-Stokes Raman spectroscopy.展开更多
文摘The direct interfacing of photonic crystal fiber to a metallic nanoantenna has widespread application in nanoscale imaging, optical lithography, nanoscale lasers, quantum communication, in vivo sensing, and medical surgery.We report on the fabrication of a needle-shaped plasmonic nanoantenna on the end facet of a photonic crystal fiber using electron-beam-induced evaporation of platinum. We demonstrate the coupling of light from the fiber waveguide mode to the subwavelength nanoantenna plasmonic mode focusing down to the apex of the plasmonic needle using a polarization-resolved far-field side-scatter imaging technique. Our work provides an important step toward widespread application of optical fibers in nearfield spectroscopic techniques such as tip-enhanced Raman and fluorescence microscopy, single-photon excitation and quantum sensors, nanoscale optical lithography, and lab-on-fiber devices.
基金National Science Foundation(NSF)(CHE-1609608)Welch Foundation(A-1261,AA-1956-20180324,A-1547)+1 种基金Baylor University(Baylor)Office of Naval Research(ONR)(N00014-16-1-2578)
文摘Two-dimensional materials are generating great interest due to their unique electrical and optical properties.In particular, transition metal dichalcogenides such as molybdenum disulfide(MoS_2) are attractive materials due to the existence of a direct band gap in the monolayer limit that can be used to enhance nonlinear optical phenomena, such as Raman spectroscopy. Here, we have investigated four-wave mixing processes in bulk MoS_2 using a multiplex coherent anti-Stokes Raman spectroscopy setup. The observed four-wave mixing signal has a resonance at approximately 680 nm, corresponding to the energy of the A excitonic transition of MoS_2. This resonance can be attributed to the increased third-order nonlinear susceptibility at wavelengths near the excitonic transition. This phenomenon could open the path to using MoS_2 as a substrate for enhancing four-wave mixing processes such as coherent anti-Stokes Raman spectroscopy.
