Division of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.
Opt Lett. 2010 Sep 15;35(18):3003-5. doi: 10.1364/OL.35.003003.
We propose a common-path lateral-shearing nulling interferometer for direct detection of exoplanets. A Savart plate is placed between crossed polarizers to produce a lateral shear and realize fully achromatic and highly stable nulling interference for starlight. We construct a double-shearing interferometer using two Savart plates for implementing orthogonal x and y shears. A laboratory demonstration is carried out using a broadband light source with a bandwidth of Δλ/λ(0)=0.33 (Δλ=0.2 μm and λ(0)=0.6 μm). As a result, achieved extinction levels are 4 × 10(-4) at peak and 4 × 10(-7) at 10λ(0)/D(L) (D(L) is the diameter of a Lyot stop).
我们提出了一种共光路横向剪切消光干涉仪，用于直接探测系外行星。在正交偏光镜之间放置一块萨伐尔（Savart）板，产生横向剪切，实现星光全消光和高度稳定的消光干涉。我们使用两块萨伐尔板构建了一个双剪切干涉仪，实现了正交的 x 和 y 剪切。利用带宽为 Δλ/λ(0)=0.33（Δλ=0.2 μm，λ(0)=0.6 μm）的宽带光源进行了实验室演示。结果，在峰值处达到的消光水平为 4 × 10(-4)，在 10λ(0)/D(L)处达到 4 × 10(-7)（D(L)是李奥（Lyot）光阑的直径）。
