Circular polarizing film

Circular polarizing film is a technologically advanced film that, from the entire light beam incident on it, only transmits the light wave polarized with a plane of polarization rotating in the appropriate direction. This phenomenon is called circular polarization, and depending on the direction of rotation, we distinguish right-handed circular polarization or left-handed circular polarization. Technically, the name of this phenomenon comes from the fact that the vector defining the plane of polarization traces a circle during one period of the wave. This is shown in the images below:

Right-handed circular polarization (*)

Left-handed circular polarization (*)

Circular polarizing film is a product in which the active layer is a suitable circular polarizer applied onto a polyethylene terephthalate (PET) film strip. The film is easy to handle and can be cut with a knife or scissors.

The film comes in two variants: with adhesive and without adhesive. The first variant has a special water-activated adhesive applied on the inner side, so no additional components are needed to stick the film.

The polarizing film can be mounted on glass and other similar flat materials (organic glass, acrylic, plexiglass). The installation is fully reversible; the film can be removed without altering the surface it was applied to.

The circular polarizing film has a protective outer layer to prevent scratching.

Circular polarizing film is used in various specialized applications:

  • as an additional polarizer in monitor and TV displays
  • in 3D glasses used for viewing three-dimensional images. One lens contains a right-handed circular polarizing film, and the other contains a left-handed circular polarizing film. This property of the polarizing film is used here: unlike linear polarization, you don’t need to keep your head perfectly perpendicular to the TV to have a sharp image. The film “works” practically in any position.
  • in photography in polarizing filters
  • to eliminate light reflections. Here we use an important property of circular polarizing film: relative to the plane wave created by reflection, the film is always effectively “perpendicular” regardless of its orientation. To remove reflection with a linear polarizer, it must be precisely set perpendicular to the reflected wave. The circular polarizing film does not have this limitation. Additionally, when eliminating reflections, the direction of polarization does not matter. Right-handed circular polarizing film works exactly the same as left-handed circular polarizing film.
(*) Images come from Wikimedia Commons – a free media repository. They were included in the article Wave polarization: https://pl.wikipedia.org/wiki/Polaryzacja_fali