Page 135 - Fundamentals of Light Microscopy and Electronic Imaging

118 PROPERTIES OF POLARIZED LIGHT

Figure 8-1
Crystals and starch grains in Amaryllis cytoplasm as seen in a polarizing microscope. The
high contrast indicates a high degree of molecular order in these structures.

that produces polarized light is called a polarizer; when used to determine the plane of
vibration, the same filter is called an analyzer. The most efficient polarizers are made of
transparent crystals such as calcite, but polarized light can also be generated simply and
economically using a partially light-absorbing sheet of linear polarizing material of the
type originally introduced by the Polaroid Corporation. Linear polarizers have a unique
transmission axis (usually marked on the plate) that defines the plane of vibration of the
transmitted rays. Polarizers also play an important role as an analytic tool for determin-