• V-coated-Laser-Windows-Flat-1

V-Coated Wedged Laser Protecting Windows

Optical windows provide protection between an optical system or sensitive electronics and an outside environment. It is important to select a window that transmits the wavelengths used in the system. In addition the substrate material should be able to withstand the environmental conditions of the application. Windows are offered in a wide range of substrates, sizes and thicknesses to meet any application need.

Paralight Optics offers V-coated laser line windows for applications which require protecting laser output while minimizing stray light and reflections. Each side of the optic features an AR coating that is centered around a common laser wavelength. These windows exhibit high damage thresholds (>15J/cm2), they are used in front of lasers for material processing in order to protect the laser optics from hot material drops. We also offer wedged laser windows.

The V-coating is a multi-layer, anti-reflective, dielectric thin-film coating designed to achieve minimal reflectance over a narrow band of wavelengths. Reflectance rises rapidly on either side of this minimum, giving the reflectance curve a “V” shape. Compared to broadband AR coatings, V-coatings achieve lower reflectance over a narrower bandwidth when used at the specified AOI. please check the following graph showing coating angular dependence for your references.





Dimension Options:

Available in Custom Sizes and Thicknesses

Coating Options:

Antireflection (AR) Coatings Centered Around Common Lasing Wavelengths

Laser Damage Quantification Test:

High Laser Damage Thresholds for Use with Lasers


Common Specifications:


Ranges & Tolerances

  • Substrate Material

    N-BK7 or UV Fused Silica

  • Type

    V-Coated Laser Protecting Window

  • Wedge Angle

    30 +/- 10 arcmin

  • Size


  • Size Tolerance

    +0.00/-0.20 mm

  • Thickness


  • Thickness Tolerance


  • Clear Aperture


  • Parallelism

    Typical: ≤ 1 arcmin | Hight Precision: ≤ 5 arcsec

  • Surface Quality (scratch-dig)

    Typical: 60-40 | High Precision: 20-10

  • Surface Flatness @ 633 nm

    ≤ λ/20 over central Ø 10mm | ≤ λ/10 over entire clear aperture

  • Transmitted Wavefront Error @ 633 nm

    Typical ≤ λ | High Precision ≤ λ/10

  • Coating

    AR coatings, Ravg < 0.5% at 0° ± 5° AOI

  • Laser Damage Threshold (for UVFS)

    >15 J/cm2 (20ns, 20Hz, @1064nm)



The AR coatings on these laser windows are specifically designed for use with common laser wavelengths and offer Ravg < 0.5% over their specified wavelength range(s) and for AOI = 0° ± 5°.
The graph to the right shows how one specific coating typically performs on the substrate of UV fused silica at various angles.
For more information on other AR coatings such as broadband of 400 - 700 nm, 523 - 532 nm, or 610 - 860 nm, 1047 - 1064 nm for N-BK7 or wavelength ranges of 261 - 266 nm, 350 - 450 nm, 1028 -1080 nm for UV fused silica, please contact us for details.