Yokoyama Shuko, Yokoyama Toshiyuki, Hagihara Yuki, Araki Tsutomu, Yasui Takeshi
Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
Opt Express. 2009 Sep 28;17(20):17324-37. doi: 10.1364/OE.17.017324.
We propose a distance meter that utilizes an intermode beat of terahertz frequency in an optical frequency comb to perform high resolution and high dynamic range absolute distance measurements. The proposed system is based on a novel method, called multiheterodyne cross-correlation detection, in which intermode beat frequencies are scaled down to radio frequencies by optical mixing of two detuned optical frequency combs with a nonlinear optical crystal. Using this method, we obtained a 1.056 THz intermode beat and achieved a distance resolution of 0.820 microm from its phase measurement. Absolute distance measurement using 1.056 THz and 8.187 GHz intermode beats was also demonstrated in the range of 10 mm, resulting in a precision of 0.688 microm.
我们提出了一种测距仪，它利用光频梳中太赫兹频率的模式间拍频来进行高分辨率和高动态范围的绝对距离测量。所提出的系统基于一种称为多外差互相关检测的新方法，在该方法中，通过将两个失谐光频梳与非线性光学晶体进行光学混频，将模式间拍频频率缩小到射频。使用该方法，我们获得了1.056太赫兹的模式间拍频，并通过其相位测量实现了0.820微米的距离分辨率。在10毫米范围内还演示了使用1.056太赫兹和8.187吉赫兹模式间拍频的绝对距离测量，精度为0.688微米。
