Rocky Mountain Instrument Co.

Optical Components:

Developed in conjunction with

Mirrors » Phase Retarding Mirrors

Phase Retarding Mirrors are designed to produce a specific phase shift between the S and P polarization components of an incident CO2 laser beam.

Mirrors designed for zero phase shift maintain the incident polarization state in the reflected beam. Mirrors designed for λ/4 (90º) phase shift convert a linearly polarized beam into a circularly polarized beam. Mirrors designed for λ/8 (45º) phase shift convert a linearly polarized beam into an elliptically polarized beam.

RMI Standard Specifications
Materials: Si, Cu
Angle of Incidence: 45º
Design Wavelength: 10.6 μm
Surface Figure: λ/40 [λ/20] at 10.6 µm, S1
Surface Quality: 40-20, S1
Fine grind, S2
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
Reflectance: R ≥ 98.5%
Retardation: 0: 0º ± 6º
λ/4: 90º ± 6º