Author Affiliations
1Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China2Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China3School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, China4University of Chinese Academy of Sciences, Beijing 100049, Chinashow less
Fig. 1. Schematic diagram for the principle of terahertz field modulated FEL induced photoelectron time and energy distribution
Fig. 2. Simulation results with delays of -60 fs, 0 fs, and 60 fs. (a)-(c) Correlation in-between the terahertz streaked photoelectron final energy and initial energy at different time delays; (d)-(f) photoelectron final energy spectrum distribution
Fig. 3. Photoelectron spectrum of FEL pulses with different lengths at the zero point of the terahertz vector potential. (a)-(c) Pulse length is 35 fs, 20 fs, and 10 fs respectively
Fig. 4. Schematic diagram for two arbitary FEL pulses with various mutual delays modulated by terahertz field near to the zero-crossing of its vector potential, where the pulse lengths are 50 fs and 35 fs. (a) Schematic diagram of double-pulse modulation by terahertz vector potential, when the double pulses are relative to the zero of terahertz vector potentials are -40 fs and 70 fs; (b) variation of center enegy of photoelectron spectrum with delays of double-pulse in Fig. (a); (c)(d) schematic diagram
Fig. 5. Relative errors between retrieval result and original FEL pulse in different lengths, deviated from the zero of terahertz vector potential from -100 fs to 100 fs
Fig. 6. Offset errors for center energy of photonelectron spectrum at different delays under an identical terahertz streaking field for FEL pulses with different pulse lengths. (a) 20 fs; (b) 10 fs
Actual pulse duration /fs | Retrieved pulse duration at different delays /fs | Spectral boradening at different delays /eV | |
---|
-60 | | 0 | 60 | -60 | 0 | 60 |
---|
50 | 44.58(-10.84%) | 49.35(-1.3%) | 52.80(+5.60%) | 6.44 | 7.41 | 8.11 | 35 | 30.95(-11.57%) | 34.56(-1.25%) | 37.21(+6.31%) | 3.79 | 4.48 | 5.00 | 20 | 17.01(-14.95%) | 19.77(-1.15%) | 21.83(+9.60%) | 1.43 | 1.85 | 2.20 | 10 | 6.87(-30.5%) | 9.92(-0.80%) | 12.13(+21.3%) | 0.27 | 0.54 | 0.78 |
|
Table 1. Retrieval results and modulation spectrum width spread of pulses with different FEL pulse widths at different delays
Delay /fs | -40 | -30 | -20 | -10 | 0 | 20 | 40 | 60 | 80 |
---|
Error /% | - | -63.6 | -32.6 | -18 | +1.6 | +23.2 | +41.4 | +61.8 | +74.6 |
|
Table 2. Retrieval errors of 5 fs FEL pulse under different delays