论文标题
透明光谱透明膜中双折射的定量测量
Quantitative measurement of birefringence in transparent films across the visible spectrum
论文作者
论文摘要
常见的透明聚合物膜（例如玻璃纸和家用胶带）经常用作教科书和教室演示中的双重材料的例子。在定性上，通常通过在交叉极化器之间分层这样的薄膜来证明双折射。在这项工作中，我们描述了一种廉价的实验设置，用于定量测量普通家庭电影中的双折射，适用于高中或本科实验室。基于极化的课堂实验的传统方法通常使用单色激光光，但我们鼓励使用不一致的白炽灯源和便携式光谱仪的联合使用。此外，我们演示了如何使用任何伴随的薄膜干扰效应来分别测量最异质和最均匀的膜中的光学厚度。鉴于对方的知识，这种测量可以用作膜的折射指数或其厚度的独立实验确认。为了提供数据分析程序的示例以及研究一系列材料，我们测量了六种常见家用聚合物膜的可见光谱中的双折射，包括薄厨房包装，玻璃纸，礼品篮膜和常见的粘合剂胶带。
Common transparent polymer films such as cellophane and household tape are frequently used as examples of birefringent materials in textbooks and classroom demonstrations. Qualitatively, birefringence is often demonstrated by layering such films between crossed-polarizers. In this work, we describe an inexpensive experimental setup for the quantitative measurement of birefringence in common household films, suitable for senior high school or undergraduate labs. Whereas traditional approaches for polarization-based classroom experiments typically use monochromatic laser light, we encourage the combined use of an incoherent incandescent light source and portable spectrometer. In addition, we demonstrate how any concomitant thin-film interference effects can be used to separately measure the optical thickness in the most heterogeneous and uniform films. Such measurement can then be used as an independent experimental confirmation of either the film's index of refraction or its thickness, given knowledge of the other. In an effort to provide examples for the data analysis procedures as well as to investigate a range of materials, we measure the birefringence across the visible spectrum of six common household polymer films, including thin kitchen wrap, cellophane, gift basket film, and common adhesive tapes.
