
148 OPTICS FOR ENGINEERS
(A)
(B) (C)
Figure 6.11 Fresnel reflection. The reflection from a polished tile floor (A) is polarized. A
polarizer blocks more than half the diffusely scattered light (B,C). If the polarizer oriented to pass
horizontal, or S, polarization with respect to the floor, then the specular reflection, is bright (B).
If the polarizer is rotated to pass vertical, or P polarization, the specular reflection is greatly
decreased (C).
Germanium is frequently used as an optical material in the infrared. Although it looks like
a mirror in the visible, it is quite transmissive for wavelengths from 2 to beyond 10 μm. With
its high index of refraction ...