Thickness and birefringence of thin films assessed by interferometry using a low-cost spectrometer

The interference has significant importance from the viewpoints of fundamental science and applications. Though the experimental exercise and assessment based on numerical data are inevitable to understand the interference, it is challenging to perform classwork using spectrometers in a large teaching room due to the high-cost problems. In this work, the authors assessed low-cost spectrometers' availability and analysis methods for transmittance/reflectivity measurements for polymer films and their educational applications. The results show the accuracy and convenience of the apparatus and the methods.