Basic polarising filter

In contrast to the normal polarising filter, the two basic polarising filters can only be set to two specific orthogonal polarisations. The grid around the polarising filter shows which polarisation direction is transmitted.

One of the two polarising filters (diagonal grid) can be set to the polarisation directions +45° and -45°. The second polarising filter (horizontal grid or vertical grid) can be set to the polarisation directions 0° and 90°. Together, the two orientations of each polarisation filter then provide a possible measurement basis. For this reason, the polarising filters are referred to as X-base polarising filters (diagonal grid) and +-base polarising filters (horizontal/vertical grid).

 

On this page you will find information on assembly, special features and possible experiments.

Assembly

Exploded view
Material:
  • 4x   01E_Go_V*_basic_polarising_filter_base
  • 2x   06A_Si_V*_basic_polarising_filter_filter_cover
  • 1x   06B_Si_V*_+basic_polarising_filter_centre
  • 1x   06C_Si_V*_xbasic_polarising_filter_centre
  • 2x   06A_Re_basic_polarising_filter_handel
  • 6x   Threaded insert, M3
  • 6x   Allen cylinder head screw, M3x12
  • 2x  Polarising filter foil 17mm x 17mm
Tools:
  • Allen key – 2,5 mm
  • Soldering iron (with melting aid)
  • Scissors (for cutting the polarising filters to size)

You will also find detailed instructions for assembly as well as a component and material list with the STL files for 3D printing and links to the relevant shops.

Special features

Alignment of the polarising filter foil

The correct alignment of the polarising filter is difficult when assembling. The Brewster angle can be used for this purpose:

The orientation of the polarising filter film can be determined using the Brewster angle, for example with a glass plate or the display of a smartphone. Hold the film in front of the reflected polarised light. The orientation of the polarising film is 0° when the reflected light is absorbed. The orientation of the polarising filter holder will help you with this: if the slots in the holder are aligned vertically, the reflected light should be absorbed; if they are aligned horizontally, it should be transmitted.

Filter cover

The filter cover is inserted into the corresponding opening after the polarising filter and snaps into place to hold the polarising filter firmly in place.

Experiments