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.
N-BK7 or UVFS
Available in Custom Sizes and Thicknesses
Antireflection (AR) Coatings Centered Around Common Lasing Wavelengths
High Laser Damage Thresholds for Use with Lasers
Substrate Material
N-BK7 or UV Fused Silica
Type
V-Coated Laser Protecting Window
Wedge Angle
30 +/- 10 arcmin
Size
Custom-made
Size Tolerance
+0.00/-0.20 mm
Thickness
Custom-made
Thickness Tolerance
+/-0.2%
Clear Aperture
>80%
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)