Duran Vicente, Djevarhidjian Leo, Guillet de Chatellus Hugues
Opt Lett. 2019 Aug 1;44(15):3789-3792. doi: 10.1364/OL.44.003789.
We present a bidirectional recirculating frequency-shifting loop, seeded by a continuous-wave (cw) laser, to perform multi-heterodyne interferometry. This fiber-optic system generates two counter-propagating "acousto-optic" frequency combs with a controllable line spacing. Apart from its simple architecture, coherent averaging allows us to reach acquisition times up to the second scale without resorting to any active stabilization mechanism. We also show that the relative phase between the combs is quadratic and can be easily controlled by adjusting the parameters of the loop. The capability of our scheme to perform molecular spectroscopy is proven by dual-comb measurements of a transition of hydrogen cyanide in the near-infrared region (1550 nm).
我们展示了一种由连续波（cw）激光注入种子光的双向循环移频环路，用于进行多外差干涉测量。这个光纤系统产生两个反向传播的“声光”频率梳，其线间距可控。除了结构简单外，相干平均使我们能够在不借助任何主动稳定机制的情况下达到秒级的采集时间。我们还表明，频率梳之间的相对相位是二次的，并且可以通过调整环路参数轻松控制。我们的方案进行分子光谱分析的能力通过在近红外区域（1550 nm）对氰化氢跃迁的双频梳测量得到了证明。
