Retardation plates

Retardation plates (also called "waveplates") are used to change the polarization type of the incident radiation by unequally phase-shifting its orthogonally polarized components. Operation is based on the birefringent linear effect, which is the difference in the refractive indices for the beams with parallel and normal polarization towards the optical axis of the crystalline quartz material being within the waveplate plane.

Quarter-Waveplates are used for conversion of linearly polarized radiation into circularly polarized radiation when the input polarization is oriented at an angle of 45° to the waveplate optical axis. Rotation of the Half-Waveplate by an angle q results in rotation of the polarization plane of the emerging radiation by a 2q angle, thus allowing the half-waveplate to be used as an adjustable rotator for the polarization plane.

The main advantages of High-Order Waveplates are their low cost and high damage threshold. However, the operational range is restricted by their temperature dependence and their narrow free spectral range. These disadvantages are reduced for Low-Order Waveplates. In contact to this, Zero-Order Waveplates are temperature independent, easy to align and can be used for a spectral band along with a single wavelength, thus being useful for tunable lasers (e.g. dye laser) or for laser diode applications.

General Specifications:

Standard Units: