Waveplate for mid-IR range
Altechna Co. Ltd.

We offer Zero order half waveplates and quarter waveplates from cadmium thiogallate (CdGa2S4) with clear aperture from 10mm up to 18mm for the range 2,8 - 9,0microns.

Dielectric AR coatings for the mid-IR range are also available in order to enhance the performance of the waveplates. Characteristic plates thickness is 0,5 - 0,9 mm. Generally, the waveplates are mounted into the metal holder for easier handling and adjustment.

Standard specifications:
Material Cadmium thiogallate (CdGa2S4)
Characteristic thickness 0,5 - 0,9 mm
Clear aperture 10mm
Surface Flatness < Lambda/4@633nm
Wedge angle between faces 1,5-3,0 arcmin (<20arcsec available upon demand)
Transparency range 0,47 - 9,5 microns
Birefringence (no-ne) ~ 0,005 at IR
Refractive index no ~ 2,3
Thermal conductivity ~ 3W/(mxK)
Damage threshold ~ 0,6 - 0,8 J/cm2 at 20ns pulses
Diameter of the metal holder 25,4 mm