The frequency characteristics of free oscillation magnetron（FOM） and injection-locked magnetron（ILM） are theoretically investigated.By using the equal power voltage obtained from the experiment data,expressions of...The frequency characteristics of free oscillation magnetron（FOM） and injection-locked magnetron（ILM） are theoretically investigated.By using the equal power voltage obtained from the experiment data,expressions of the frequency and radio frequency（RF） voltage of FOM and ILM,as well as the locking bandwidth,on the anode voltage and magnetic field are derived.With the increase of the anode voltage and the decrease of the magnetic field,the power and its growth rate increase,while the frequency increases and its growth rate decreases.The theoretical frequency and power of FOM agree with the particle-in-cell（PIC） simulation results.Besides,the theoretical trends of the power and frequency with the anode voltage and magnetic field are consistent with the experimental results,which verifies the accuracy of the theory.The theory provides a novel calculation method of frequency characteristics.It can approximately analyze the power and frequency of both FOM and ILM,which promotes the industrial applications of magnetron and microwave energy.展开更多
We report on the amplification of high-average-power and high-efficiency picosecond pulses in a self-made verylarge-mode-area Yb-doped photonic crystal fiber（PCF）. The PCF with a core diameter of 105 μm and a core ...We report on the amplification of high-average-power and high-efficiency picosecond pulses in a self-made verylarge-mode-area Yb-doped photonic crystal fiber（PCF）. The PCF with a core diameter of 105 μm and a core numerical aperture of 0.05 is prepared by the sol-gel method combined with the powder sintering technique. The fiber amplification system produces the highest average power of 255 W at a 10 MHz repetition rate with a 21 ps pulse duration corresponding to a peak power of 1.2 MW. This result exemplifies the high-average-power and high-peak-power potential of this specifically designed fiber.展开更多
We experimentally demonstrate a cascaded Raman scattering continuum, utilizing a compact mode-locked Yb-doped fiber laser based on a nonlinear polarization rotation technique in the all normal dispersion regime.There ...We experimentally demonstrate a cascaded Raman scattering continuum, utilizing a compact mode-locked Yb-doped fiber laser based on a nonlinear polarization rotation technique in the all normal dispersion regime.There is no physical filter or polarization controller in the oscillator, and a different mode-locked operation is achieved, corresponding to the extra fiber location in the oscillator. The broadband spectrum generation owes to the enhanced stimulated Raman scattering progress. The maximum output average power and peak power are14.75 n J and 18.0 W, and the short coherence light is suited for optical coherence tomography.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2013CB328901)the National Natural Science Foundation of China(Grant No.11305177)
文摘The frequency characteristics of free oscillation magnetron（FOM） and injection-locked magnetron（ILM） are theoretically investigated.By using the equal power voltage obtained from the experiment data,expressions of the frequency and radio frequency（RF） voltage of FOM and ILM,as well as the locking bandwidth,on the anode voltage and magnetic field are derived.With the increase of the anode voltage and the decrease of the magnetic field,the power and its growth rate increase,while the frequency increases and its growth rate decreases.The theoretical frequency and power of FOM agree with the particle-in-cell（PIC） simulation results.Besides,the theoretical trends of the power and frequency with the anode voltage and magnetic field are consistent with the experimental results,which verifies the accuracy of the theory.The theory provides a novel calculation method of frequency characteristics.It can approximately analyze the power and frequency of both FOM and ILM,which promotes the industrial applications of magnetron and microwave energy.
基金supported by the National“863”Program of China(No.2014AA041901)the National Natural Science Foundation of China(Nos.U1330134 and 61308024)
文摘We report on the amplification of high-average-power and high-efficiency picosecond pulses in a self-made verylarge-mode-area Yb-doped photonic crystal fiber（PCF）. The PCF with a core diameter of 105 μm and a core numerical aperture of 0.05 is prepared by the sol-gel method combined with the powder sintering technique. The fiber amplification system produces the highest average power of 255 W at a 10 MHz repetition rate with a 21 ps pulse duration corresponding to a peak power of 1.2 MW. This result exemplifies the high-average-power and high-peak-power potential of this specifically designed fiber.
基金supported by the National Natural Science Foundation of China(No.61575011)the Key Project of the National Natural Science Foundation of China(No.61235010)
文摘We experimentally demonstrate a cascaded Raman scattering continuum, utilizing a compact mode-locked Yb-doped fiber laser based on a nonlinear polarization rotation technique in the all normal dispersion regime.There is no physical filter or polarization controller in the oscillator, and a different mode-locked operation is achieved, corresponding to the extra fiber location in the oscillator. The broadband spectrum generation owes to the enhanced stimulated Raman scattering progress. The maximum output average power and peak power are14.75 n J and 18.0 W, and the short coherence light is suited for optical coherence tomography.
