Compare Model Drawings, CAD & Specs Diameter Edge Thickness Coating Type OEM Compatibility Availability Price
1.0 in. 3 mm 90PS
2.0 in. 10.16 mm 90PS Trumpf
2.67 in. 20.32 mm 90PS-HR Trumpf
1.5 in. 4 mm 90PS
2.0 in. 9.52 mm 90PS
3.0 in. 6.35 mm 90PS-HR Amada
3.0 in. 9.52 mm 90PS
2.0 in. 5.08 mm 90PS-HR Amada
1.75 in. 9.52 mm 90PS
2.5 in. 6.35 mm 90PS N -Tanaka


  • Type
    90° Phase Shift Mirror
  • Optic Material
    Silicon (Si)
  • S1 Radius
  • S2 Radius
  • Surface Quality
    10-5 scratch and dig
  • Surface Irregularity
    1 Fringes @ 633 nm
  • Power
    2 Fringes @ 633 nm
  • Diameter Tolerance
    +0 / -0.12 mm
  • Thickness Tolerance
    ±0.25 mm
  • Wedge
    <3' (arc minutes)


90° Phase Shift Mirrors

Most CO2 lasers produce a laser beam which has linear polarization. For cutting metal sheets, however, a beam with circular polarization is required if the cutting properties are independent of the cutting direction. To convert a beam from linear to circular polarization, a 90° phase retarder mirror (also called a Lambda/4-mirror) can be used. This mirror has a special coating which produces a phase shift of 90° between the s-and p-polarized components of the reflected beam. If these components have the same intensity and phase (corresponding to linear polarization), the reflected beam undergoes a phase shift of 90° between both components (corresponding to linear polarization).

High Thermal Conductivity Copper Substrate

In order to optimize function of these mirrors, different substrate materials are used - the most common ones are silicon (Si) and copper (Cu). Silicon mirrors have light weight and are therefore preferred in flying optics where high accelerations are needed. Copper has high thermal conductivity, and channels for cooling water can be included directly into the CO2 laser mirrors. Therefore, copper mirrors are preferred if best-possible cooling is important, for example in CO2 laser machines with very high laser power.

90 Phase Shift Mirror Coatings

The optical properties of a mirror (reflectance, phase shift, etc.) are determined by its coating. In order to realize different mirror functions, different coatings are needed.

The new 90º Phase Shift High Reflection (90PS-HR) coating features higher reflection compared to standard 90PS coating, resulting in less power loss and increased life expectancy. This is an improvement over our standard 90º phase shift coating, reducing absorption level by 50% and setting it to be lower the 1%. This superior absorption level is achieved with no compromise in the phase shift performance (tolerance ±2º) or visible light (630-670 nm) reflection. This coating becomes our standard for 90º phase shift mirrors.

Coating Substrate %R@45°@10.6 %R@45°@Visible Phase Shift@45°
90PS Si&Cu 98% ≥80%@630-670 nm 90°±2°
90PS-HR Si&Cu 99% ≥80%@632.8 nm 90°±2°

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