Brewster windows operate at an angle of incidence equal to the ‘Brewster angle’ which is 67.4 degrees for ZnSe at 10.6mm. In order to present a square profile to the incident beam, they are about 2.5 times longer than their width. They fully transmit linearly polarized light in the P-plane and reflect about 50% of the S-plane component. Consequently, they can be used to enhance (‘clean-up’) the polarization or by rotating it about the beam axis, they can be used as an attenuator. Coated versions enhance the reflectance of the S-component but at the expense of restricting the power. Usually, Brewster windows are used in pairs.

  • Wedged to between 3 and 5 arcminutes in order to overcome multiple interference
  • Coated or uncoated versions and many sizes available
  • Also available in matched wedge pairs

The following Brewster windows are currently available.  Others may be available upon request.

Part NoMaterialDiameterETCoating
ZBW2510ZnSe25mm3mmUncoated ZnSe
ZBW3315ZnSe33mm3mmUncoated ZnSe
ZBW4218ZnSe42mm3mmUncoated ZnSe
ZBW5018ZnSe50mm3mmUncoated ZnSe
ZBW5320ZnSe53mm3mmUncoated ZnSe
ZBW6122ZnSe61mm3mmUncoated ZnSe
ZBW6323ZnSe63mm3mmUncoated ZnSe
ZBW6625ZnSe66mm3mmUncoated ZnSe
ZBW10038ZnSe100mm3mmUncoated ZnSe
ZBW11542ZnSe115mm3mmUncoated ZnSe
ZBW13248ZnSe132mm3mmUncoated ZnSe

Brewster window


ULO Optics is an ISO certified company and quality is at the heart of everything we do.  With a host of industrial affiliations you can rely on ULO to deliver.