Schweinberger Wolfgang, Vamos Lenard, Xu Jia, Hussain Syed A, Baune Christoph, Rode Sebastian, Pupeza Ioachim
Opt Express. 2019 Feb 18;27(4):4789-4798. doi: 10.1364/OE.27.004789.
Precise delay control is of paramount importance in optical pump-probe measurements. Here, we report on a high-precision delay tracking technique for mechanical scanning measurements in a Mach-Zehnder interferometer configuration. The setup employs a 1.55-µm continuous-wave laser beam propagating along the interferometer arms. Sinusoidal phase modulation at 30 MHz, and demodulation of the interference signal at the fundamental frequency and its second harmonic, enables delay tracking with sampling rates of up to 10 MHz. At an interferometer arm length of 1 m, root-mean-square error values of the relative delay tracking below 10 attoseconds for both stationary and mechanically scanned (0.2 mm/s) operation are demonstrated. By averaging several scans, a precision of the delay determination better than 1 as is reached. We demonstrate this performance with a mechanical chopper periodically interrupting one of the interferometer arms, which opens the door to the combination of high-sensitivity lock-in detection with (sub-)attosecond-precision relative delay determination.
在光泵浦 - 探测测量中，精确的延迟控制至关重要。在此，我们报道一种用于马赫 - 曾德尔干涉仪配置下机械扫描测量的高精度延迟跟踪技术。该装置采用沿干涉仪臂传播的1.55微米连续波激光束。30兆赫兹的正弦相位调制以及对基频及其二次谐波处干涉信号的解调，使得能够以高达10兆赫兹的采样率进行延迟跟踪。在干涉仪臂长为1米时，展示了在静止和机械扫描（0.2毫米/秒）操作下相对延迟跟踪的均方根误差值低于10阿秒。通过对多次扫描进行平均，延迟测定精度达到优于1阿秒。我们通过机械斩波器周期性中断干涉仪的一个臂来展示这种性能，这为将高灵敏度锁定检测与（亚）阿秒精度相对延迟测定相结合打开了大门。
