Measuring Carrier-Envelope Phase of Few-Cycle Laser Pulses Using High-Order Above-Threshold Ionization Photoelectrons
DENG Yong-Kai1, LI Min1, YU Ji-Zhou1, LIU Yuan-Xing1, LIU Yun-Quan1,2**, GONG Qi-Huang1,2
1Department of Physics and State Key Laboratory for Mesoscopic Physics, Peking University, Beijing 100871 2Collaborative Innovation Center of Quantum Matter, Beijing 100871
Abstract：We experimentally demonstrate the measurement of carrier-envelope phase of few-cycle laser pulses. We have built a stereo above-threshold ionization setup. The photoelectron energy spectra of high-order above-threshold ionization are measured in both the left and right directions in the linearly polarized laser fields. It is shown that the left-right asymmetry of the spectra is dependent on carrier-envelope phase of few-cycle laser pulses. Two asymmetry parameters from the low-energy and high-energy regions at the above-threshold ionization plateau map a phase ellipse, in which the points indicate the absolute value of carrier-envelope phase. We have calibrated the phase ellipse by comparison with the semiclassical calculation. This setup allows us to determine the value of the absolute phase of few-cycle laser pulses.
2014, Vol. 31 
