Niwa Yoshito, Arai Koji, Ueda Akitoshi, Sakagami Masaaki, Gouda Naoteru, Kobayashi Yukiyasu, Yamada Yoshiyuki, Yano Taihei
Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan.
Appl Opt. 2009 Nov 10;48(32):6105-10. doi: 10.1364/AO.48.006105.
A heterodyne metrology interferometer was stabilized down to a noise level of 20 picometers (pm) as a root-mean-square (RMS) value integrated between 0.3 mHz and 1 Hz. This noise level was achieved by employing active and passive interferometer stabilization techniques. The heterodyne interferometer was built on a 50 mm square ultralow expansion glass plate in order to reduce an optical path length change caused by temperature variation. An optical configuration of the interferometer is a Mach-Zehnder interferometer with a design as symmetric as possible so that a detection signal can be insensitive to homogeneous thermal expansion of the glass plate. The heterodyne frequency is actively controlled in order to suppress residual noises caused by optical path length changes outside of the glass plate as well as phase fluctuations of the heterodyne frequency source. Our stabilization scheme is considered useful in achieving the 20 pm noise level without a stable heterodyne frequency source, as well as temperature stabilization around a whole apparatus. This interferometer can be used in precise metrology applications, such as characterization of deformation for satellite optical components against thermal exposure.
一台外差计量干涉仪被稳定到均方根（RMS）值为20皮米（pm）的噪声水平，该值是在0.3毫赫兹至1赫兹之间积分得到的。通过采用主动和被动干涉仪稳定技术实现了这一噪声水平。外差干涉仪构建在一块50毫米见方的超低膨胀玻璃板上，以减少温度变化引起的光程长度变化。干涉仪的光学配置是马赫曾德尔干涉仪，其设计尽可能对称，以便检测信号对玻璃板的均匀热膨胀不敏感。为了抑制玻璃板外部光程长度变化以及外差频率源的相位波动所引起的残余噪声，外差频率受到主动控制。我们的稳定方案被认为对于在没有稳定外差频率源的情况下实现20皮米的噪声水平以及整个设备周围的温度稳定是有用的。这种干涉仪可用于精密计量应用，例如表征卫星光学部件在热暴露下的变形情况。
