Zhang Hongyuan, Wei Haoyun, Wu Xuejian, Yang Honglei, Li Yan
Opt Express. 2014 Mar 24;22(6):6597-604. doi: 10.1364/OE.22.006597.
A dual-comb nonlinear asynchronous optical sampling method is proposed to simplify determination of the time interval and extend the non-ambiguity range in absolute length measurements. Type II second harmonic generation facilitates curve fitting in determining the time interval between adjacent pulses. Meanwhile, the non-ambiguity range is extended by adjusting the repetition rate of the signal laser. The performance of the proposed method is compared with a heterodyne interferometer. Results show that the system achieves a maximum residual of 100.6 nm and an uncertainty of 1.48 μm in a 0.5 ms acquisition time. With longer acquisition time, the uncertainty can be reduced to 166.6 nm for 50 ms and 82.9 nm for 500 ms. Moreover, the extension of the non-ambiguity range is demonstrated by measuring an absolute distance beyond the inherent range determined by the fixed repetition rate.
提出了一种双梳状非线性异步光学采样方法，以简化时间间隔的确定，并在绝对长度测量中扩展无模糊范围。II型二次谐波产生有助于在确定相邻脉冲之间的时间间隔时进行曲线拟合。同时，通过调整信号激光的重复频率来扩展无模糊范围。将所提出方法的性能与外差干涉仪进行了比较。结果表明，该系统在0.5 ms的采集时间内实现了100.6 nm的最大残余误差和1.48 μm的不确定度。采集时间越长，不确定度可分别降至50 ms时的166.6 nm和500 ms时的82.9 nm。此外，通过测量超出由固定重复频率确定的固有范围的绝对距离，证明了无模糊范围的扩展。
