Large Aperture Retarder

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Large Aperture Retarder

For many astronomical, aerospace, and defense projects, large aperture retarders are required. Meadowlark Optics has over thirty-five years of retarder manufacturing expertise and is able to manufacture from a wide variety of materials to facilitate high or low power applications.
Waveplates up to 150 mm diameter are available. Some materials allow retarders to be used over different wavelengths from the ultraviolet, through the visible and into the near infrared.
  • RAPtor Applied Polymer Retarders
  • Large 6” Outer Diameter
  • Less than 15mm Thickness
  • True Zero-Order
  • Broad Wavelength ranges
Meadowlark Optics uses proprietary methods to ensure the best spatial uniformity of its polymer and crystalline retarders. These retarders have a spatial uniformity of better than two percent across the clear aperture and with the correct substrates, can have a wavefront distortion that is on par with Meadowlark Optics’ Precision Retarders.
Meadowlark Optic’s liquid crystal variable retarders can also be built with large clear apertures. Please contact your Meadowlark Optics Sales Engineer for assistance and a custom quote.


  • Outer diameter up to 6 inches
  • Clear aperture > 90%
  • Custom size, retardance and wavelength range available
  • Spatial uniformity of less than 2% across clear aperture
  • Various materials available: (polymer, quartz, sapphire, magnesium fluoride and liquid crystal)


Specifications - Large Aperture Retarders
Retarder (Bifringent) Material Options

Crystalline Quartz
Magnesium Fluoride
Liquid Crystal†

Wavelength 300-2500 nm (specify)
Retardances 0 to 100s of λ
Retardance Accuracy
Spatial Uniformity
≤ λ/100 to ≤ λ/350
≤ λ/10 to ≤ λ/100
Transmitted Wavefront Distortion
≤ λ to ≤ λ/5 (P-V @ 633)
[ λ/4 to λ/20 (RMS @ 633)]
Surface Quality 40-20 scratch-dig to
80-50 scratch-dig
Outside Dimensions up to 150 mm
Nematic Liquid Crystals are also available but with different specifcations that those listed.
Specifications are design dependent, depending on the materials chosen, outside dimensions requested and other specifications. Not all of these specifications are possible together.
Contact your Meadowlark Optics Sales Engineer for a custom quote.

Ordering Information - Large Aperture Retarders
Large Aperture retarders are available in a variety of different sizes and shapes with custom retardances at specific wavelengths. Combinations of different materials allow custom achromatic, athermal or wide angle designs. Please contact your Meadowlark Optics Sales Engineer for a custom quote.