Metallic ND Filter, UV Fused Silica, 25.4 mm, 0.4 OD at 632.8 nm

  • Size
    Ø25.4 mm
  • Wavelength Range
    350 - 2000 nm
  • Optical Density
    0.4
  • Optical Density Tolerance
    ±5% @ 632.8 nm
  • Transmission
    39.8% @ 632.8 nm
  • Angle of Incidence
  • Material
    UV grade fused silica or equivalent
  • Damage Threshold
    30 W/cm2 CW, typical; not recommended for pulsed laser use
  • Size Tolerance
    ±0.25 mm
  • Thickness
    3.0 mm
  • Thickness Tolerance
    ±0.25 mm
  • Surface Flatness
    ≤1λ at 632.8 nm over the clear aperture
  • Surface Quality
    60-40 scratch-dig
  • Clear Aperture
    ≥central 80% of dimensions
  • Wedge
    ≤3 arc min
  • Chamfers
    0.25–0.76 mm face width
  • Chamfers Angle Tolerance
    45° ±15°
  • Durability
    MIL-C-48497A, adhesion, humidity, moderate abrasion, and solubility requirements
  • Cleaning