Flat supercontinuum in the telecommunication wave bands of E+S+C is generated by coupling a train of femtosecond pulses generated by a mode-locked Ti:sapphire laser into the fundameutal mode of a photonic crystal fibe...Flat supercontinuum in the telecommunication wave bands of E+S+C is generated by coupling a train of femtosecond pulses generated by a mode-locked Ti:sapphire laser into the fundameutal mode of a photonic crystal fiber with central holes fabricated in our lab. The pulse experiences the anomalous dispersion regime,and the soliton dynamic effect plays an important role in supercontinuum generation.The output spectrum in the wavelength range of 1360 1565nm does not include significant ripples due to higher pump peak power,and the normalized intensity shows less fluctuation.展开更多
The various mode effective indices of the doped photonic crystal fibers (PCFs) are compared, the mode field distributions of the fundamental mode and the second-order mode are analyzed, and the single-mode condition i...The various mode effective indices of the doped photonic crystal fibers (PCFs) are compared, the mode field distributions of the fundamental mode and the second-order mode are analyzed, and the single-mode condition is presented. The mode effective indices of large-core doped PCFs with different core indices and structure parameters are simulated by the finite element method (FEM). The relations of the core index with the fiber structure parameters of pitch, hole-to-pitch ratio and core diameter are obtained for single-mode propagation. In the design and fabrication of the doped PCF, we can adjust the core index and fiber structure parameters to achieve large mode area and single-mode propagation.展开更多
Blue-shifted dispersive waves(DWs)are efficiently generated from the red-shifted solitons by coupling the 120 fs pulses into the fundamental mode of the multi-knots of a photonic crystal fiber cladding.When the femtos...Blue-shifted dispersive waves(DWs)are efficiently generated from the red-shifted solitons by coupling the 120 fs pulses into the fundamental mode of the multi-knots of a photonic crystal fiber cladding.When the femtosecond pulses at the wavelength of 825 nm and the average power of 300 mW are coupled into knots 1–3,the conversion efficiencyηDW of 32%and bandwidth BDW of 50 nm are obtained.The ultrashort pulses generated by the DWs can be tunable over the whole visible wavelength by adjusting the wavelengths of the pump pulses coupled into different knots.It can be believed that this widely wavelength-tunable ultrashort visible pulse source has important applications in ultrafast photonics and resonant Raman scattering.展开更多
The ultraviolet continuum generation in the fundamental mode of photonic crystal fibers designed and fabricated in our lab are experimentally demonstrated.When the pump works in the normal dispersion regions of 780 nm...The ultraviolet continuum generation in the fundamental mode of photonic crystal fibers designed and fabricated in our lab are experimentally demonstrated.When the pump works in the normal dispersion regions of 780 nm and 830 nm,and the average powers increase from 100 to 500 m W,anti-Stokes signals can be efficiently generated based on the phase-matched degenerate four-wave mixing.The cross-phase modulation between the pump and the generated anti-Stokes signals can effectively extend the continuum into the ultraviolet wavelength range.This can provide an efficient light source for ultraviolet photonics and spectroscopy.展开更多
基金Supported by the Key Program of the National Natural Science Foundation of China under Grant No 60637010the National Basic Research Program of China under Grant Nos 2010CB327604 and 2010CB327604Qinhuangdao Science and Technology Research and Development Program under Grant No 201101A093.
文摘Flat supercontinuum in the telecommunication wave bands of E+S+C is generated by coupling a train of femtosecond pulses generated by a mode-locked Ti:sapphire laser into the fundameutal mode of a photonic crystal fiber with central holes fabricated in our lab. The pulse experiences the anomalous dispersion regime,and the soliton dynamic effect plays an important role in supercontinuum generation.The output spectrum in the wavelength range of 1360 1565nm does not include significant ripples due to higher pump peak power,and the normalized intensity shows less fluctuation.
基金This work has been supported by the National Basic Research Program of China （No.2010CB327604）, the National Natural Science Foundation of China （Nos.60978028, 61201110 and 61205084）, the Science and Technology Development Program of Hebei Province （No. 12211015）, and the Science and Technology Development Program of Qinhuangdao （Nos.2012021A130 and 201001A087）.
文摘The various mode effective indices of the doped photonic crystal fibers (PCFs) are compared, the mode field distributions of the fundamental mode and the second-order mode are analyzed, and the single-mode condition is presented. The mode effective indices of large-core doped PCFs with different core indices and structure parameters are simulated by the finite element method (FEM). The relations of the core index with the fiber structure parameters of pitch, hole-to-pitch ratio and core diameter are obtained for single-mode propagation. In the design and fabrication of the doped PCF, we can adjust the core index and fiber structure parameters to achieve large mode area and single-mode propagation.
基金Supported by the National Basic Research Program of China(2010CB327605,2010CB328300)the Key Grant of Ministry of Education(109015)+3 种基金the Program for New Century Excellent Talents in University(NECT-11-0596)Beijing Nova Program(2011066)the Fundamental Research Funds for the Central Universities(2011RC008,2011RC0404)Open Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications).
文摘Blue-shifted dispersive waves(DWs)are efficiently generated from the red-shifted solitons by coupling the 120 fs pulses into the fundamental mode of the multi-knots of a photonic crystal fiber cladding.When the femtosecond pulses at the wavelength of 825 nm and the average power of 300 mW are coupled into knots 1–3,the conversion efficiencyηDW of 32%and bandwidth BDW of 50 nm are obtained.The ultrashort pulses generated by the DWs can be tunable over the whole visible wavelength by adjusting the wavelengths of the pump pulses coupled into different knots.It can be believed that this widely wavelength-tunable ultrashort visible pulse source has important applications in ultrafast photonics and resonant Raman scattering.
基金Supported by the Key Program of the National Natural Science Foundation of China under Grant No 60637010,the National Basic Research Program of China under Grant No 2010CB327604the Shanghai Leading Academic Discipline Program under Grant No S30105the Natural Science Foundation of Hebei Provice under Grant No F2009000465.
文摘The ultraviolet continuum generation in the fundamental mode of photonic crystal fibers designed and fabricated in our lab are experimentally demonstrated.When the pump works in the normal dispersion regions of 780 nm and 830 nm,and the average powers increase from 100 to 500 m W,anti-Stokes signals can be efficiently generated based on the phase-matched degenerate four-wave mixing.The cross-phase modulation between the pump and the generated anti-Stokes signals can effectively extend the continuum into the ultraviolet wavelength range.This can provide an efficient light source for ultraviolet photonics and spectroscopy.
