Polariserare

Polariserare, or polarizers, are optical devices that transmit light with a specific polarization while attenuating or blocking orthogonal polarization components. For unpolarized light, passage through a linear polarizer results in light that is polarized along its transmission axis. The intensity of transmitted light depends on the relative orientation of the incoming polarization and the polarizer axis, described by Malus's law: I_out = I_in cos^2(theta).

Types include linear polarizers, circular polarizers, and polarising beam splitters. Linear polarizers transmit one linear polarization and reject the orthogonal component. Circular polarizers combine a linear polarizer with a quarter-wave plate to transmit or analyze circular polarization, common in photography to reduce reflections and to adjust color saturation. Polarising beam splitters separate light into two orthogonal polarizations that travel in different directions. Materials vary and include dichroic polymers, calcite-based prisms, and nano-structured wire grids for infrared and microwave wavelengths.

Applications include photography, liquid crystal displays, microscopy, astronomy, metrology, and 3D display systems. In research, polarizers enable polarization analysis, ellipsometry, and stress testing in materials science. In daily life, polarising sunglasses and camera filters are common examples.

Performance depends on transmittance, extinction ratio, wavelength coverage, and incidence angle. Real polarizers exhibit wavelength-dependent behavior and losses, and may require calibration for accurate polarization analysis. Cost, temperature stability, and environmental durability also influence selection.