Flare frequency distributions represent a key approach to addressing one of the largest problems ... more Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counterintuitively heats coronae to temperatures that are orders of magnitude hotter than the corresponding photospheres. It is widely accepted that the magnetic field is responsible for the heating, but there are two competing mechanisms that could explain it: nanoflares or Alfvén waves. To date, neither can be directly observed. Nanoflares are, by definition, extremely small, but their aggregate energy release could represent a substantial heating mechanism, presuming they are sufficiently abundant. One way to test this presumption is via the flare frequency distribution, which describes how often flares of various energies occur. If the slope of the power law fitting the flare frequency distribution is above a critical threshold, α = 2 as established in prior literature, then there should be a sufficient abundance of nanofla...
Flare frequency distributions represent a key approach to addressing one of the largest problems ... more Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counterintuitively heats coronae to temperatures that are orders of magnitude hotter than the corresponding photospheres. It is widely accepted that the magnetic field is responsible for the heating, but there are two competing mechanisms that could explain it: nanoflares or Alfvén waves. To date, neither can be directly observed. Nanoflares are, by definition, extremely small, but their aggregate energy release could represent a substantial heating mechanism, presuming they are sufficiently abundant. One way to test this presumption is via the flare frequency distribution, which describes how often flares of various energies occur. If the slope of the power law fitting the flare frequency distribution is above a critical threshold, α = 2 as established in prior literature, then there should be a sufficient abundance of nanofla...
This erratum corrects typographical errors that appeared in Eqs. (1.1) and (1.2) of our earlier p... more This erratum corrects typographical errors that appeared in Eqs. (1.1) and (1.2) of our earlier paper [Optica 6, 716 (2019)OPTIC82334-253610.1364/OPTICA.6.000716.
We report a ∼3-fold enhancement of third-harmonic generation (THG) conversion efficiency using in... more We report a ∼3-fold enhancement of third-harmonic generation (THG) conversion efficiency using indium tin oxide (ITO) nanoparticles on the surface of an ultra-high-Q silica microsphere. This is one of the largest microcavity-based THG enhancements reported. Phase-matching and spatial mode overlap are explored numerically to determine the microsphere radius (∼29 µm) and resonant mode numbers that maximize THG. Furthermore, the ITO nanoparticles are uniformly bonded to the cavity surface by drop-casting, eliminating the need for complex fabrication. The significant improvement in THG conversion efficiency establishes functionalized ITO microcavities as a promising tool for broadband frequency conversion, nonlinear enhancement, and applications in integrated photonics.
We report observation of cavity-enhanced photo-induced writing of gratings, and Kerr nonlinearity... more We report observation of cavity-enhanced photo-induced writing of gratings, and Kerr nonlinearity-induced symmetry breaking and erasing of selective grating in an As2S3 microsphere.
2020 Conference on Lasers and Electro-Optics (CLEO), 2020
We report Ge<inf>23</inf>Sb<inf>7</inf>S<inf>70</inf> chalcog... more We report Ge<inf>23</inf>Sb<inf>7</inf>S<inf>70</inf> chalcogenide wedge resonators with a high quality factor and broadband dispersion which is induced by an exceedingly smooth and varying-angle wedge surface.
We report a ~3x increase in third-harmonic generation conversion efficiency using indium tin oxid... more We report a ~3x increase in third-harmonic generation conversion efficiency using indium tin oxide (ITO) nanoparticles on the surface of a silica microsphere. This establishes ITO-microresonators as a promising tool for applications in nonlinear optics.
Reconfigurable optical devices provide new opportunities for integrated photonics. The use of cha... more Reconfigurable optical devices provide new opportunities for integrated photonics. The use of chalcogenide glasses, with large refractive index nonlinearity and photosensitivity, in conjunction with the microresonator platform has proven to be a powerful tool in the study and application of nanophotonics. Here, we report cavity-enhanced photo-induced writing and erasing of gratings in a chalcogenide As2S3 microresonator. Grating writing is implemented with self-enhanced standing wave modes, while the erasing of written gratings as well as removing of intrinsic back-scattering is achieved by Kerr-nonlinearity-induced symmetry breaking in the microresonator. These findings pave the way for future reconfigurable photonic devices and reveal exciting new possibilities for nonlinear photonics and microresonators.
We present a novel method to quantify the nonlinear refractive index, optical absorption and back... more We present a novel method to quantify the nonlinear refractive index, optical absorption and back-scattering in microresonators, by measuring the transmission spectra as a function of time and fitting it using a genetic algorithm.
We report an Indium Tin Oxide (ITO) nanoparticle-coated silica microsphere with a high nonlinear ... more We report an Indium Tin Oxide (ITO) nanoparticle-coated silica microsphere with a high nonlinear refractive index and quality factor. The nonlinear index of the coated microresonator is 5 times higher than the uncoated ones.
Flare frequency distributions represent a key approach to addressing one of the largest problems ... more Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counterintuitively heats coronae to temperatures that are orders of magnitude hotter than the corresponding photospheres. It is widely accepted that the magnetic field is responsible for the heating, but there are two competing mechanisms that could explain it: nanoflares or Alfvén waves. To date, neither can be directly observed. Nanoflares are, by definition, extremely small, but their aggregate energy release could represent a substantial heating mechanism, presuming they are sufficiently abundant. One way to test this presumption is via the flare frequency distribution, which describes how often flares of various energies occur. If the slope of the power law fitting the flare frequency distribution is above a critical threshold, α = 2 as established in prior literature, then there should be a sufficient abundance of nanofla...
Flare frequency distributions represent a key approach to addressing one of the largest problems ... more Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counterintuitively heats coronae to temperatures that are orders of magnitude hotter than the corresponding photospheres. It is widely accepted that the magnetic field is responsible for the heating, but there are two competing mechanisms that could explain it: nanoflares or Alfvén waves. To date, neither can be directly observed. Nanoflares are, by definition, extremely small, but their aggregate energy release could represent a substantial heating mechanism, presuming they are sufficiently abundant. One way to test this presumption is via the flare frequency distribution, which describes how often flares of various energies occur. If the slope of the power law fitting the flare frequency distribution is above a critical threshold, α = 2 as established in prior literature, then there should be a sufficient abundance of nanofla...
This erratum corrects typographical errors that appeared in Eqs. (1.1) and (1.2) of our earlier p... more This erratum corrects typographical errors that appeared in Eqs. (1.1) and (1.2) of our earlier paper [Optica 6, 716 (2019)OPTIC82334-253610.1364/OPTICA.6.000716.
We report a ∼3-fold enhancement of third-harmonic generation (THG) conversion efficiency using in... more We report a ∼3-fold enhancement of third-harmonic generation (THG) conversion efficiency using indium tin oxide (ITO) nanoparticles on the surface of an ultra-high-Q silica microsphere. This is one of the largest microcavity-based THG enhancements reported. Phase-matching and spatial mode overlap are explored numerically to determine the microsphere radius (∼29 µm) and resonant mode numbers that maximize THG. Furthermore, the ITO nanoparticles are uniformly bonded to the cavity surface by drop-casting, eliminating the need for complex fabrication. The significant improvement in THG conversion efficiency establishes functionalized ITO microcavities as a promising tool for broadband frequency conversion, nonlinear enhancement, and applications in integrated photonics.
We report observation of cavity-enhanced photo-induced writing of gratings, and Kerr nonlinearity... more We report observation of cavity-enhanced photo-induced writing of gratings, and Kerr nonlinearity-induced symmetry breaking and erasing of selective grating in an As2S3 microsphere.
2020 Conference on Lasers and Electro-Optics (CLEO), 2020
We report Ge<inf>23</inf>Sb<inf>7</inf>S<inf>70</inf> chalcog... more We report Ge<inf>23</inf>Sb<inf>7</inf>S<inf>70</inf> chalcogenide wedge resonators with a high quality factor and broadband dispersion which is induced by an exceedingly smooth and varying-angle wedge surface.
We report a ~3x increase in third-harmonic generation conversion efficiency using indium tin oxid... more We report a ~3x increase in third-harmonic generation conversion efficiency using indium tin oxide (ITO) nanoparticles on the surface of a silica microsphere. This establishes ITO-microresonators as a promising tool for applications in nonlinear optics.
Reconfigurable optical devices provide new opportunities for integrated photonics. The use of cha... more Reconfigurable optical devices provide new opportunities for integrated photonics. The use of chalcogenide glasses, with large refractive index nonlinearity and photosensitivity, in conjunction with the microresonator platform has proven to be a powerful tool in the study and application of nanophotonics. Here, we report cavity-enhanced photo-induced writing and erasing of gratings in a chalcogenide As2S3 microresonator. Grating writing is implemented with self-enhanced standing wave modes, while the erasing of written gratings as well as removing of intrinsic back-scattering is achieved by Kerr-nonlinearity-induced symmetry breaking in the microresonator. These findings pave the way for future reconfigurable photonic devices and reveal exciting new possibilities for nonlinear photonics and microresonators.
We present a novel method to quantify the nonlinear refractive index, optical absorption and back... more We present a novel method to quantify the nonlinear refractive index, optical absorption and back-scattering in microresonators, by measuring the transmission spectra as a function of time and fitting it using a genetic algorithm.
We report an Indium Tin Oxide (ITO) nanoparticle-coated silica microsphere with a high nonlinear ... more We report an Indium Tin Oxide (ITO) nanoparticle-coated silica microsphere with a high nonlinear refractive index and quality factor. The nonlinear index of the coated microresonator is 5 times higher than the uncoated ones.
Uploads