We demonstrate an all-optical method for time-domain characterization of ultrashort optical pulses using nonionizing lasers. A moderately intense laser pulse couples the doubly excited states of helium and induces the ac Stark effect. A synchronized weak signal field perturbs the coupling process and alters the quasienergies of the dressed atom, upon which the carrier oscillation of the signal field is encoded. The nonionizing lasers used in current approach minimize plasma-induced pulse distortion and provide a complementary detection scheme for effective and reliable optical oscilloscope.

中文翻译：

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扰动交流Stark效应用于阿秒光学波形采样

我们展示了使用非电离激光器对超短光脉冲进行时域表征的全光学方法。中等强度的激光脉冲耦合氦的双重激发态，并引起交流斯塔克效应。同步的弱信号场会干扰耦合过程，并改变修整原子的准能，在此基础上对信号场的载波振荡进行编码。当前方法中使用的非电离激光器使等离子体引起的脉冲畸变最小，并为有效和可靠的光学示波器提供了互补的检测方案。