Optics Essentials

4	Manipulation of Light

This chapter describes light that is manipulated by a medium or obstruction. Many of the optical phenomena we observe are a direct cause of light encountering an object or a medium other than propagating in vacuum.

4.1    REFLECTION

4.1.1      REFLECTION FROM FLAT MIRROR

As observed in our daily experience, light rays reflect, namely, change direction and travel back, when they encounter a smooth surface, such as glass or a polished metal. The reflection angle from a polished surface, such as glass or a front-surface mirror, is equal to the incident angle, both measured from the surface normal, as shown in Figure 4.1. Namely,

${\text{θ}}_r={\text{θ}}_i$

(4.1)

where θ_i is the incident angle, and θ_r is the reflection angle.

For a curved ...