Polarization Gratings Technical Details


  • Efficiency:  Up to 99% diffraction efficiency (less than 1% leakage into the zero order), up to 95% transmittance
  • Typical Diffraction Angles: up to ±20˚ (higher angles possible for custom applications)
  • Typical Bandwidths (narrowband type): ±6% around 1550nm, 800nm, 633nm, 532nm, or 455nm; other wavelengths custom
  • Typical Bandwidths (broadband type): 450-650nm, 500-900nm, 1-4 µm; other wavelength ranges custom
  • Size: up to 300 x 300mm sq; round samples custom
  • Wavefront: lambda/5 typical, up to lambda/30 custom


PGs have 99% diffraction efficiency in most cases, and propagate both polarizations in a “forward” direction, making them uniquely suited as polarization elements and beam splitting elements. Additionally, PGs combined with LC cells are ideal for polarization-based switching elements because they “re-direct” light into one of two directions depending on the polarization state of the incident light.

Additional Information

We pioneered the defect-free PG starting in 2005 and we are the pioneer of broadband techniques through multiple twists. We use these principles to tailor nearly any achromatic and chromatic spectra and we enjoy the challenge of tailoring our technology to new applications. If you have a unique optical challenge that doesn’t exactly fit our typical specifications, we encourage you to contact us to explore what is possible.

Polarization Gratings (PGs) are basis for IO technology platforms

  • Polarized diffraction
    • Right & left circular
    • +/- 1st orders only
  • Highly efficient
    • Low leakage: <1%
  • Tunable operation
    • Broadband
    • Narrowband
  • Wide Angle Version Available
Polarization Grating RHC LHC
Image of PG output and measurements


  • Periodic Optical Axis formed in LCs
  • Affects the Geometric Phase
    (not conventional phase or Bragg)
  • Polarizing Beam Splitter
    (with excellent LCP/RCP)

Theory Predictions, Exp. Confirmed

  • 100% single-order diffraction
  • Polarization-sensitive 1st orders
  • ~ 500 lines/mm and smaller (≥ 2 µm period)
  • Wide wavelength tuning (350 – 5000 nm)

Best of “thick” and “thin” gratings.

  • 1st order efficiency ratio depends on circular polarizations
  • 0th order efficiency depends only on PG construction
  • Polarization of 1st order is always orthogonal to input circular
  • Dependent

PG Efficiency with Respect to Input Angle

  • Dependent on grating period and wavelength
  • Leakage increases with angle
  • Small grating periods have higher sensitivity
  • Large grating periods can be fairly insensitive
  • In general falloff of efficiency is relatively slow
Image of PG Diffraction Efficiency
Graphic of Conventional PG
Line drawing of multiple PG configurations

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