We present a numerical and experimental study of the propagation characteristics of photonic crystal fibers(PCFs)selectively filled with ionic liquid(IL;1-butyl-3-methylimidazolium iodine).Three types of IL-filled PCF...We present a numerical and experimental study of the propagation characteristics of photonic crystal fibers(PCFs)selectively filled with ionic liquid(IL;1-butyl-3-methylimidazolium iodine).Three types of IL-filled PCF are investigated:one with all air holes filled,one with an IL-filled air hole in the second ring,and one with an IL-filled air hole in the third ring.The results show that the third type of IL-filled PCF is the most sensitive to temperature;the sensitivity of resonant dips between the LP01 and LP21 modes is−2.9 nm/XC.Moreover,the intensity of the resonant dips changes with the polarization angle of the light source;the sensitivity is−0.79 dB per unit polarization angle.Based on this property,IL-filled PCFs with different utilities can be realized by changing the filling position flexibly.Consequently,IL-filled PCFs can be used under flexible conditions and controllable temperatures to create a compact polarization-angle sensor.展开更多
We present a review of the development of a compact and high-power broadband terahertz （THz） source optically excited by a femtosecond photonic crystal fiber （PCF） amplifier.The large mode area of the PCF and the ...We present a review of the development of a compact and high-power broadband terahertz （THz） source optically excited by a femtosecond photonic crystal fiber （PCF） amplifier.The large mode area of the PCF and the stretcher-free configuration make the pump source compact and very efficient.Broadband THz pulses of 150 μW extending from 0.1 to 3.5 THz are generated from a 3-mm-thick GaP crystal through optical rectification of 12-W pump pulses with duration of 66 fs and a repetition rate of 52 MHz.A strong saturation effect is observed,which is attributed to pump pulse absorption;a Z-scan measurement shows that three-photon absorption dominates the nonlinear absorption when the crystal is pumped by femtosecond pulses at 1 040 nm.A further scale-up of the THz source power is expected to find important applications in THz nonlinear optics and nonlinear THz spectroscopy.展开更多
基金supported partly by the National Natural Science Foundation of China(Grant Nos.11804171,11674177,and 61775107)partly by the Natural Science Foundation of Tianjin,China(Grant No.16JCZDJC31000)partly by the Self-made Experiment Teaching Instrument Project of Nankai University 2018(Grant No.2018NKZZYQ04).
文摘We present a numerical and experimental study of the propagation characteristics of photonic crystal fibers(PCFs)selectively filled with ionic liquid(IL;1-butyl-3-methylimidazolium iodine).Three types of IL-filled PCF are investigated:one with all air holes filled,one with an IL-filled air hole in the second ring,and one with an IL-filled air hole in the third ring.The results show that the third type of IL-filled PCF is the most sensitive to temperature;the sensitivity of resonant dips between the LP01 and LP21 modes is−2.9 nm/XC.Moreover,the intensity of the resonant dips changes with the polarization angle of the light source;the sensitivity is−0.79 dB per unit polarization angle.Based on this property,IL-filled PCFs with different utilities can be realized by changing the filling position flexibly.Consequently,IL-filled PCFs can be used under flexible conditions and controllable temperatures to create a compact polarization-angle sensor.
基金supported partly by the National Natural Science Foundation of China (Nos. 61077083, 61027013,61078028,and 60838004)the National Basic Research Program of China (Nos. 2007CB310408, 2010CB327604,and 2011CB808101)+3 种基金the Research Fund for the Doctoral Program of Higher Education (No. 200800560026)the Foundation for the Author of National Excellent Doctoral Dissertation of China (No. 2007B34)the 111 Project (No. B07014)the Program for New Century Talents in University (No. NCET-07-0597)
文摘We present a review of the development of a compact and high-power broadband terahertz （THz） source optically excited by a femtosecond photonic crystal fiber （PCF） amplifier.The large mode area of the PCF and the stretcher-free configuration make the pump source compact and very efficient.Broadband THz pulses of 150 μW extending from 0.1 to 3.5 THz are generated from a 3-mm-thick GaP crystal through optical rectification of 12-W pump pulses with duration of 66 fs and a repetition rate of 52 MHz.A strong saturation effect is observed,which is attributed to pump pulse absorption;a Z-scan measurement shows that three-photon absorption dominates the nonlinear absorption when the crystal is pumped by femtosecond pulses at 1 040 nm.A further scale-up of the THz source power is expected to find important applications in THz nonlinear optics and nonlinear THz spectroscopy.
