Ultraprecise Measurement of Thermal Expansion Coefficients — Recent Progress
Ultraprecise Measurement of Thermal Expansion Coefficients — Recent Progress
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热膨胀系数的超精密测量——最新进展
DOI：
10.1063/1.2948558
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发表时间：
1972
影响因子：
5.6
通讯作者：
J. Osmundsen
中科院分区：
文献类型：
--
作者：
S. Jacobs;J. W. Berthold;J. Osmundsen
已经开发出一种测量小位移的技术。该方法依赖于多光束光干涉，样品用作法布里-珀罗标准子间隔。通过在电域中监测光干涉的热诱导变化，可以实现极高的精度。方法如下：使用频率稳定激光器探测法布里-珀罗标准子的共振，该标准子的反射镜与样品的末端光学接触。入射光束经过电光调制，在其上留下边带，边带可以在频率上移动，直到与法布里-佩罗传输峰值重合。当样品温度改变一个量ΔT，随后的长度变化ΔL导致法布里-佩罗共振位移一个量Δν = (ν/L)ΔL。这种调制频率的变化与热膨胀系数α≡(1/ΔT)（ΔL/L） = (1/ΔT)（Δν/ν）有关。对于小的α值，测量精度受到激光频率稳定性的限制。
A technique has been developed for measurement of small displacements. The method relies on multiple beam optical interference, with the sample used as a Fabry‐Perot etalon spacer. Extreme precision is made possible by monitoring in the electrical domain the thermally induced changes in optical interference. The method is as follows: A frequency stable laser is used to probe the resonances of a Fabry‐Perot etalon whose mirrors are optically contacted to the ends of the sample. The incident beam is electro‐optically modulated to impress sidebands on it which can be moved in frequency until one coincides with a Fabry‐Perot transmission peak. When the sample temperature is changed an amount ΔT the subsequent length change ΔL causes the Fabry‐Perot resonances to shift an amount Δν = (ν/L)ΔL. This change in modulation frequency is related to the thermal expansion coefficient α ≡ (1/ΔT) (ΔL/L) = (1/ΔT)(Δν/ν). For small values of α the precision of measurement is limited by the laser's frequency stability, which...