PbS-doped glasses are prepared. Absorption and luminescence spectra show that both the absorption and infrared emission can be tuned widely by thermal treatment conditions. Optical amplification at 1300 nm is observed...PbS-doped glasses are prepared. Absorption and luminescence spectra show that both the absorption and infrared emission can be tuned widely by thermal treatment conditions. Optical amplification at 1300 nm is observed, and amplified spontaneous emission （ASE） spectrum is also measured to confirm the optical gain from PbS quantum dots.展开更多
Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（C...Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.展开更多
The localized surface plasmon resonance properties of Al and Alcore/Al2O3shell nanosphere dimers with Al and Al core nanosphere radii of 20 nm and Al2O3 shell of 2 nm in the deep-ultraviolet region have been studied u...The localized surface plasmon resonance properties of Al and Alcore/Al2O3shell nanosphere dimers with Al and Al core nanosphere radii of 20 nm and Al2O3 shell of 2 nm in the deep-ultraviolet region have been studied using the finite difference time domain method. The extinction spectra and the electric field distribution profiles of the two dimers for various gap distances between two individual nanospheres are compared with those of the corresponding monomers to reveal the extent of plasmon coupling. It is found that with the interparticle distance decreasing, a strong plasmon coupling between two Al or Alcore/Al2O3shell nanospheres is observed accompanied by a significant red shift in the extinction spectra at the parallel polarization direction of the incident light related to the dimer axis, while for the case of the perpendicular polarization direction, a weak plasmon coupling arises characterized by a slight blue shift in the extinction spectra. The electric field distribution profiles show that benefiting from the dielectric Al2O3 shell, the gap distance of Alcore/Al2O3shell nanosphere dimers can be tailored to 〈 1 nm scale and results in a very high electric field enhancement. The estimated surface-enhanced Raman scattering enhancement factors suggests that the Alcore/Al2O3shell nanosphere dimers with the gap of 〈 1 nm gave rise to an enhancement as high as 8.1 × 10^7 for interparticle gap = 0.5 nm. Our studies reveal that the Alcore/Al2O3shell nanosphere dimers may be promising substrates for surface-enhanced spectroscopy in the deep-ultraviolet region.展开更多
In a Gaussian laser beam pumped single-photon frequency up-conversion system, the spatial distribution of the con- version efficiency is calculated, which strongly depends on the intensity distribution of the pump bea...In a Gaussian laser beam pumped single-photon frequency up-conversion system, the spatial distribution of the con- version efficiency is calculated, which strongly depends on the intensity distribution of the pump beam and leads to a spatial modulation of the output single photons. As a result, by simply varying the Gauss/an pump beam intensity and the beam size, the converted photons could be modulated spatially and exhibit a programmable distribution. This will be meaningful for the researches on quantum communication and quantum manipulation based on frequency up-conversion svstem.展开更多
We report a time-of-flight photon-counting imaging system in conjunction with a single-photon detector mounted with a fiber optic taper, which equivalently enlarges the active area of the single-photon detector by 100...We report a time-of-flight photon-counting imaging system in conjunction with a single-photon detector mounted with a fiber optic taper, which equivalently enlarges the active area of the single-photon detector by 100 times. The field of view of the imaging system is extended from ±0.57° to ±7° by using the fiber optic taper to collect the scattered photons. Since only a single avalanche photodiode is used, the noise level of the system is maintained at a low level. We demonstrate the scanning of the targets at a stand-off distance of 28 m with a centimeter depth resolution.展开更多
We investigate the strong coupling from 5,5’,6,6’-tetrachloro-1,1’-diethyl-3,3’-di(4-sulfobutyl)-benzimidazolocarbocyanine(TDBC)molecules near pure nano-triangular Ag prisms or Ag@Au hollow nanoshells.When TDBC mo...We investigate the strong coupling from 5,5’,6,6’-tetrachloro-1,1’-diethyl-3,3’-di(4-sulfobutyl)-benzimidazolocarbocyanine(TDBC)molecules near pure nano-triangular Ag prisms or Ag@Au hollow nanoshells.When TDBC molecules are deposited on pure Ag nanoprisms or Ag@Au hollow nanoshells with the plasmonic resonance peak,matching very closely with the absorption band of TDBC J-aggregates,obvious Rabi splitting can be observed due to the strong coupling regime.Meanwhile,the photoluminescence intensity decreased with the increasing of the temperature,verifying the decreasing plasmon-exciton coupling interaction in the higher temperature.Our experimental results are coincident with the simulation results calculated by finite-difference time-domain method.展开更多
As the application of orbital angular momentum(OAM) of photon quantum in quantum communication, the OAM photon quantum interface for the transmission wavelength from the telecom communication quantum information stora...As the application of orbital angular momentum(OAM) of photon quantum in quantum communication, the OAM photon quantum interface for the transmission wavelength from the telecom communication quantum information storage in visible regime is required. Here we demonstrate the efficiency enhancement for the OAM photon quantum interface based on the frequency upconversion from telecom wavelength to visible regime by sum-frequency generation. The infrared photons at 1 558 nm carrying different OAM values could be converted to the visible regime at 622.2 nm with the optimal efficiency via adjusting the pump beam waist radius and intensity.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 60778039, the National Basic Research Programme of China under Grant No 2006CB806007, and the Programme for Changjiang Scholars and Innovative Research Team in University （IRT0651）.
文摘PbS-doped glasses are prepared. Absorption and luminescence spectra show that both the absorption and infrared emission can be tuned widely by thermal treatment conditions. Optical amplification at 1300 nm is observed, and amplified spontaneous emission （ASE） spectrum is also measured to confirm the optical gain from PbS quantum dots.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11774095,11722431 and 11621404the Shanghai Basic Research Project under Grant No 18JC1412200+2 种基金the National Key R&D Program of China under Grant No2016YFB0400904the Program of Introducing Talents of Discipline to Universities under Grant No B12024the Shanghai International Cooperation Project under Grant No 16520710600
文摘Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.
基金supported by the National Natural Science Foundation of China(Grant Nos.11104079 and 61378033)the National Key Scientific Instrument Project of China(Grant No.2012YQ150092)+1 种基金the Research Foundation for the Doctoral Program of Higher Education of China(Grant No.20110076120019)the State Key Laboratory of Luminescent Materials and Devices at South China University of Technology
文摘The localized surface plasmon resonance properties of Al and Alcore/Al2O3shell nanosphere dimers with Al and Al core nanosphere radii of 20 nm and Al2O3 shell of 2 nm in the deep-ultraviolet region have been studied using the finite difference time domain method. The extinction spectra and the electric field distribution profiles of the two dimers for various gap distances between two individual nanospheres are compared with those of the corresponding monomers to reveal the extent of plasmon coupling. It is found that with the interparticle distance decreasing, a strong plasmon coupling between two Al or Alcore/Al2O3shell nanospheres is observed accompanied by a significant red shift in the extinction spectra at the parallel polarization direction of the incident light related to the dimer axis, while for the case of the perpendicular polarization direction, a weak plasmon coupling arises characterized by a slight blue shift in the extinction spectra. The electric field distribution profiles show that benefiting from the dielectric Al2O3 shell, the gap distance of Alcore/Al2O3shell nanosphere dimers can be tailored to 〈 1 nm scale and results in a very high electric field enhancement. The estimated surface-enhanced Raman scattering enhancement factors suggests that the Alcore/Al2O3shell nanosphere dimers with the gap of 〈 1 nm gave rise to an enhancement as high as 8.1 × 10^7 for interparticle gap = 0.5 nm. Our studies reveal that the Alcore/Al2O3shell nanosphere dimers may be promising substrates for surface-enhanced spectroscopy in the deep-ultraviolet region.
基金supported by the National Natural Science Foundation of China(Nos.61127014,61378033 and 11434005)the National Key Scientific Instrument Project(No.2012YQ150092)+2 种基金the Program of Introducing Talents of Discipline to Universities(No.B12024)the Shanghai Rising-Star Program(No.13QA1401300)the Shanghai International Cooperation Project(No.13520720700)
文摘In a Gaussian laser beam pumped single-photon frequency up-conversion system, the spatial distribution of the con- version efficiency is calculated, which strongly depends on the intensity distribution of the pump beam and leads to a spatial modulation of the output single photons. As a result, by simply varying the Gauss/an pump beam intensity and the beam size, the converted photons could be modulated spatially and exhibit a programmable distribution. This will be meaningful for the researches on quantum communication and quantum manipulation based on frequency up-conversion svstem.
基金supported by the National Natural Science Foundation of China(Nos.11774095,11374105,61378033 and 11621404)the Program of Introducing Talents of Discipline to Universities(No.B12024)+1 种基金the Shanghai International Cooperation Project(No.16520710600)the Shuguang Program by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.15SG22)
文摘We report a time-of-flight photon-counting imaging system in conjunction with a single-photon detector mounted with a fiber optic taper, which equivalently enlarges the active area of the single-photon detector by 100 times. The field of view of the imaging system is extended from ±0.57° to ±7° by using the fiber optic taper to collect the scattered photons. Since only a single avalanche photodiode is used, the noise level of the system is maintained at a low level. We demonstrate the scanning of the targets at a stand-off distance of 28 m with a centimeter depth resolution.
基金supported by the National Key R&D Program of China(No.2017YFA0303403)the National Natural Science Foundation of China(Nos.11874015,12074012,11674099+2 种基金11722431)the Shanghai International CooperationProject(No.16520710600)the Program of Introducing Talents of Discipline to Universities(No.B12024)。
文摘We investigate the strong coupling from 5,5’,6,6’-tetrachloro-1,1’-diethyl-3,3’-di(4-sulfobutyl)-benzimidazolocarbocyanine(TDBC)molecules near pure nano-triangular Ag prisms or Ag@Au hollow nanoshells.When TDBC molecules are deposited on pure Ag nanoprisms or Ag@Au hollow nanoshells with the plasmonic resonance peak,matching very closely with the absorption band of TDBC J-aggregates,obvious Rabi splitting can be observed due to the strong coupling regime.Meanwhile,the photoluminescence intensity decreased with the increasing of the temperature,verifying the decreasing plasmon-exciton coupling interaction in the higher temperature.Our experimental results are coincident with the simulation results calculated by finite-difference time-domain method.
基金supported by the National Natural Science Foundation of China(Nos.61378033 and 91021014)the Shuguang Program(No.15SG22)by Shanghai Education Development Foundation and Shanghai Municipal Education Commissionthe Open Project of State Key Laboratory of Precision Spectroscopy
文摘As the application of orbital angular momentum(OAM) of photon quantum in quantum communication, the OAM photon quantum interface for the transmission wavelength from the telecom communication quantum information storage in visible regime is required. Here we demonstrate the efficiency enhancement for the OAM photon quantum interface based on the frequency upconversion from telecom wavelength to visible regime by sum-frequency generation. The infrared photons at 1 558 nm carrying different OAM values could be converted to the visible regime at 622.2 nm with the optimal efficiency via adjusting the pump beam waist radius and intensity.
