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.

    利用白熾燈發出的大入射角的光照射CD或DVD上，可以觀察到一條清晰的綠線。顏色會隨著圓盤角度的輕微變化而變化。請解釋和研究這一現象。