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.

    利用白炽灯发出的大入射角的光照射CD或DVD上，可以观察到一条清晰的绿线。颜色会随着圆盘角度的轻微变化而变化。请解释和研究这一现象。