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
The effective index of the cladding fundamental space-filling mode in photonic crystal fiber (PCF) is simulated by the effective index method. The variation of the effective index with the structure parameters of the ...The effective index of the cladding fundamental space-filling mode in photonic crystal fiber (PCF) is simulated by the effective index method. The variation of the effective index with the structure parameters of the fiber is achieved. For the first time, the relations of the V parameter of Yb3+-doped PCF with the refractive index of core and the structure parameters of the fiber are provided. the single-mode characteristics of large-core Yb3+-doped photonic crystal fibers with 7 and 19 missing air holes in the core are analyzed. The large-core single-mode Yb3+-doped photonic crystal fibers with core diameters of 50 μm, 100 μm and 150 μm are designed. The results provide theory instruction for the design and fabrication of fiber.展开更多
The electronic structures and optical properties of oligothiophene substituted spirofluorenes are investigated theoretically with semi-empirical quantum chemical calculations. A theoretical investigation of the intera...The electronic structures and optical properties of oligothiophene substituted spirofluorenes are investigated theoretically with semi-empirical quantum chemical calculations. A theoretical investigation of the interaction between two perpendicular π-systems of various oligothiophene substituted spirofluorenes is conducted. The results demonstrate that the interaction be- tween two perpendicular branches is reduced by oligothiophene substitutions. Photoexcitation induced relaxation is mainly located on one of the equivalent branches or the branch with longer conjugation length. In addition to these benefits brought by 9,9-spirobifluorene center, the specific oligothiophene moieties linked to the spirt center also have properties of significant merit, such as the ability to tune energy levels and emission colors by controlling the conjugation length.展开更多
We investigate theoretically single photon transport properties in coupled-resonator waveguide coupling with a nanocavity interacting with an external mirror. By using the discrete coordinates approach, transmission a...We investigate theoretically single photon transport properties in coupled-resonator waveguide coupling with a nanocavity interacting with an external mirror. By using the discrete coordinates approach, transmission and reflection amplitudes of the propagating single photon in the waveguide are obtained. The influence of the coupling strength between the nanocavity and the external mirror on the single photon scattering spectra is discussed. We also extend the results to the waveguide with linear and quadratic form dispersion relations.展开更多
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.60637010 and 60978028)the National Basic Research Program of China (No.2010CB327604)+1 种基金the Young Scientists Fund of the Natural Science Foundation of Hebei Province (Nos.F2010001313 andF2010001291)the Science and Technology Development Program of Qinhuangdao of Hebei Province (No.201001A076)
文摘The effective index of the cladding fundamental space-filling mode in photonic crystal fiber (PCF) is simulated by the effective index method. The variation of the effective index with the structure parameters of the fiber is achieved. For the first time, the relations of the V parameter of Yb3+-doped PCF with the refractive index of core and the structure parameters of the fiber are provided. the single-mode characteristics of large-core Yb3+-doped photonic crystal fibers with 7 and 19 missing air holes in the core are analyzed. The large-core single-mode Yb3+-doped photonic crystal fibers with core diameters of 50 μm, 100 μm and 150 μm are designed. The results provide theory instruction for the design and fabrication of fiber.
基金financially supported by the National Basic Research Program of China (Grant No. 2009CB930601)the National Natural Science Foundation of China (Grant Nos. 20804020, 60976019, 50903028 and 20974046)+2 种基金the Program for New Century Excellent Talents in University (Grant No. NCET-07-0446)the Scientific and Technological Innovation Teams of Colleges and Universities in Jiangsu Province (Grant No. TJ207035)the Scientific Research Foundation of Nanjing University of Posts and Telecommunications (Grant No. NY210017)
文摘The electronic structures and optical properties of oligothiophene substituted spirofluorenes are investigated theoretically with semi-empirical quantum chemical calculations. A theoretical investigation of the interaction between two perpendicular π-systems of various oligothiophene substituted spirofluorenes is conducted. The results demonstrate that the interaction be- tween two perpendicular branches is reduced by oligothiophene substitutions. Photoexcitation induced relaxation is mainly located on one of the equivalent branches or the branch with longer conjugation length. In addition to these benefits brought by 9,9-spirobifluorene center, the specific oligothiophene moieties linked to the spirt center also have properties of significant merit, such as the ability to tune energy levels and emission colors by controlling the conjugation length.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11105001 and 61472282the Anhui Provincial Natural Science Foundation under Grant Nos.1408085QA22,1608085MA09,and 1508085MF129
文摘We investigate theoretically single photon transport properties in coupled-resonator waveguide coupling with a nanocavity interacting with an external mirror. By using the discrete coordinates approach, transmission and reflection amplitudes of the propagating single photon in the waveguide are obtained. The influence of the coupling strength between the nanocavity and the external mirror on the single photon scattering spectra is discussed. We also extend the results to the waveguide with linear and quadratic form dispersion relations.
