4. Coloured Line

When a compact disc or DVD is illuminated with light coming from a filament lamp in such a way that only rays with large angles of incidence are selected, a clear green line can be observed. The colour varies upon slightly changing the angle of the disc. Explain and investigate this phenomenon.

1. CD或DVD光盘的结构如何？有怎样的线度（大小）的周期性结构？哪些结构或者特征是我们在实验室用光学等方法可以测量的？
2. 实验中，为何选用类似白炽灯的复色光？单色光照明，会有怎样的现象？涉及到的物理过程是啥？和波长有依赖性吗？
3. 实验系统需要精密调节吗？
4. 用什么作探测器？

欢迎选课题的同学！ — 乐永康 2022/09/16 15:19