Rocky Mountain Instrument Co.

Optical Components:

Developed in conjunction with

Polarizers » Thin Film Plate Polarizers, IR

IR Thin Film Plate Polarizers were developed specifically for use in high power CO2 laser applications. Designed to operate at Brewster’s Angle, they separate an incident, unpolarized, monochromatic beam into its S and P polarization components.

The extinction ratio (Tp/Ts) exceeds 100:1 in the transmitted beam. Maximum efficiency is achieved by fine angular tuning of the plate about θB.

These all dielectric coatings are highly sensitive to wavelength and angle of incidence.

RMI Standard Specifications
Materials: ZnSe, Ge, Chalcogenide glass
Angle of Incidence:
Ge, Chalcogenide glass:
Brewster’s Angle (θB)
67.4° at 10.6 µm
76.0° at 10.6 µm
Design Wavelength: 10.6 μm
Surface Figure:
λ/40 at 10.6 µm, both surfaces
Surface Quality:
40 – 20, both surfaces
Diameter Tolerance: + 0.000", – 0.010"
Thickness Tolerance: ± 0.010"
Wedge: ≤ 3 arc minutes
Bevels: 0.010" – 0.030" at 45º
Clear Aperture: Central 85% of diameter
Rs ≥ 99%
Tp ≥ 90%
Extinction Ratio:
Tp/Ts ≥ 100:1