Huang P S
Department of Mechanical Engineering, State Uuniversity of New York at Stony Brook, Stony Brook, New York 11794-2300, USA.
Appl Opt. 1999 Aug 1;38(22):4831-6. doi: 10.1364/ao.38.004831.
We propose to use thin films to provide a drastic improvement of measurement sensitivity in the recently developed small-angle measurement method, namely, angle measurement based on the internal-reflection effect. By designing the thin films (single layer or multiple layers) so that they provide an antireflection effect in the vicinity of the critical angle, we show that the sensitivity of angle measurement can be increased exponentially with the increase of the number of thin-film layers. This method provides a new means of designing angle sensors with increased sensitivities without having to increase the number of reflections and therefore the physical size and the required fabrication accuracy of the reflection prisms. We describe the design of the thin films for this particular application and the analysis of measurement sensitivity and range as determined by the material and the number of layers of the thin films. Selection of the optimal initial angle for high linearity performance is also discussed.
我们提议使用薄膜来大幅提高最近开发的小角度测量方法（即基于内反射效应的角度测量）的测量灵敏度。通过设计薄膜（单层或多层），使其在临界角附近提供抗反射效果，我们表明角度测量的灵敏度会随着薄膜层数的增加而呈指数增长。这种方法提供了一种设计具有更高灵敏度的角度传感器的新途径，而无需增加反射次数，从而无需增加反射棱镜的物理尺寸和所需的制造精度。我们描述了针对这一特定应用的薄膜设计，以及由薄膜材料和层数所决定的测量灵敏度和范围分析。还讨论了为实现高线性性能而选择最佳初始角度的问题。
