Absolute-phase phenomena in photoionization with few-cycle laser pulses
Absolute-phase phenomena in photoionization with few-cycle laser pulses
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DOI：
10.1038/35102520
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发表时间：
2001-11-08
期刊：
影响因子：
64.8
通讯作者：
De Silvestri, S
中科院分区：
文献类型：
--
作者：
Paulus, GG;Grasbon, F;De Silvestri, S
目前，在可见光谱中可以产生的最短激光脉冲(1)由少于两个光周期组成（在脉冲包络线的半最大值的全宽度处测量）。这种脉冲中电场的时间变化取决于载波频率相对于包络线的相位——绝对相位。因为强烈的激光-物质相互作用通常依赖于脉冲的电场，所以绝对相位对于许多非线性过程是重要的（2-8）。但绝对相位效应的明确证据尚未在实验中发现，主要是因为在强大的激光脉冲中难以稳定绝对相位。在这里，我们使用一种不需要相位稳定的技术来实验证明短激光脉冲的绝对相位对光电子发射的影响。原子被短激光脉冲电离，光电子被两个相对的探测器记录在垂直于激光束的平面上。我们在电子产率的弹对弹分析中发现了反相关。
Currently, the shortest laser pulses(1) that can be generated in the visible spectrum consist of fewer than two optical cycles (measured at the full-width at half-maximum of the pulse's envelope). The time variation of the electric field in such a pulse depends on the phase of the carrier frequency with respect to the envelope- the absolute phase. Because intense laser-matter interactions generally depend on the electric field of the pulse, the absolute phase is important for a number of nonlinear processes(2-8). But clear evidence of absolute-phase effects has yet to be detected experimentally, largely because of the difficulty of stabilizing the absolute phase in powerful laser pulses. Here we use a technique that does not require phase stabilization to demonstrate experimentally the influence of the absolute phase of a short laser pulse on the emission of photoelectrons. Atoms are ionized by a short laser pulse, and the photoelectrons are recorded with two opposing detectors in a plane perpendicular to the laser beam. We detect an anticorrelation in the shot-to-shot analysis of the electron yield.