Polarized Light Microscopes (PLM)

Polarized light microscopes (often also referred to as petrographic microscopes, asbestos microscopes, crystal microscopes, forensic microscopes, polymer microscopes, ore microscopes, and more) utilize the contrast-enhancing technique known as polarized light to improve image contrast and quality, especially on samples containing anisotropic or birefringent material. Polarized light microscopy positions two polarizing filters, called polarizers, in the light path. The polarizing filters are very similar to those found on polarizing sunglasses. Ideally, both polarizers will be rotatable. One polarizer is positioned before the sample, and the second (called the analyzer) is located between the back focal plane of the objective and the eyepieces (or camera). Polarized light is used in a variety of applications and for many different types of samples. Polarized light is very popular in geology, mineralogy, and crystallography, but it has also found a home in forensic science, food science, ceramics, metallurgy, polymer science, pharmaceuticals, asbestos identification and more. Polarized light can be found on upright and inverted microscopes and it can be used with transmitted or reflected illumination. Polarized light is needed in order to use Differential Interference Contrast (DIC), and it provides some of the most beautiful, colorful, widely used images in all of science.