Vikuiti™ Circular Polarising Filters
A circular polariser comprises a linear polariser and a 1/4 wave retarder whose slow and fast axes are at
45° to the axis of the polariser. A ray of unpolarised light, passing through the linear polariser, becomes
polarised at 45° to the axis of the retarder. When this polarised light ray passes through the retarder its
vibration direction is made to move in a helical pattern. After the light ray is reflected from a specular
surface the sense of rotation of the vibration reverses. This rotation is stopped in the return through the
retarder. The light ray is now linearly polarised in a plane 90° to its original polarisation plane, and is
absorbed by the linearly polarised component of the circular polariser. A circular polariser effectively acts
like a light valve blocking light completely and therefore offers the ultimate in contrast enhancement.
