Waveplates

Retardation plates offer the possibility to adjust the polarization of a laser beam specifically without beam deflection. Birefringent materials, such as crystalline quartz, are used for this purpose. Due to the refractive index difference of the crystal axes, the s- and p-polarized portion of the light are retarded to different extents.

The use of λ/4 plates allows linearly polarised light to be converted into circularly polarised light. By using λ/2 plates, linearly polarised light can be rotated by a selectable angle. The helicity changes when λ/2 plates are used with circularly polarised light.

The retardation can be adjusted via high-precision fabrication of the material thickness and thus the desired polarization effect can be realized.

• Typical substrate material: quartz crystal
• Wavelength range: approx. 200 nm to 3 µm
• Maximum possible diameter: 40 mm
• Material thicknesses from approx. 100 µm can be produced.

The two polished surfaces are extremely plane-parallel and are anti-reflective for the respective functional wavelength.