Contrasting Techniques
Reflected-light – polarization contrast (POL)
Suitable for surfaces with structures which change the state of polarization during reflection, e.g. structure grains in samples of ore.

Beam Path Polarization contrast in reflected light
The illuminating light (1) hits a polarizer (2,P) first and is imaged, linearly polarized, on the sample surface (5). Behind the beam splitter, it hits the analyzer (6,A), which allows only the depolarized portion of the light to reach the tube lens (7). As in transmitted light, an optional lambda plate (6a,λ) enables the changeover from grey contrast to color contrast. When objectives of a very low magnification are used, a so-called Antiflex cap (a rotatable λ/4-Platte in front of the objective) permits otherwise unavoidable reflection to be also eliminated from “dark” sample surfaces.

application brightfieldapplication polarization contrast
The inner structure of these spherulites is barely visible in reflected-light brightfield.The structure in the polished iron sample becomes clearly visible in polarization contrast.
Top

back

Bright field
Dark field
Polarization contrast
DIC