Compare Model Drawings, CAD & Specs Size Optical Density Availability Price
$29
In Stock
Ø12.7 mm 0.04
In Stock
$29
In Stock
Ø12.7 mm 0.2
In Stock
$29
In Stock
Ø12.7 mm 0.4
In Stock
$29
In Stock
Ø12.7 mm 0.6
In Stock
$29
In Stock
Ø12.7 mm 0.8
In Stock
$29
In Stock
Ø12.7 mm 1
In Stock
$29
In Stock
Ø12.7 mm 2
In Stock
$29
In Stock
Ø12.7 mm 3
In Stock
$38
In Stock
Ø25.4 mm 0.04
In Stock
$38
In Stock
Ø25.4 mm 0.1
In Stock
$38
In Stock
Ø25.4 mm 0.15
In Stock
$38
3 Weeks
Ø25.4 mm 0.2
3 Weeks
$38
1 Week
Ø25.4 mm 0.3
1 Week
$38
3 Weeks
Ø25.4 mm 0.4
3 Weeks
$38
In Stock
Ø25.4 mm 0.5
In Stock
$38
In Stock
Ø25.4 mm 0.6
In Stock
$38
In Stock
Ø25.4 mm 0.7
In Stock
$38
In Stock
Ø25.4 mm 0.8
In Stock
$38
In Stock
Ø25.4 mm 0.9
In Stock
$38
In Stock
Ø25.4 mm 1
In Stock
$38
In Stock
Ø25.4 mm 1.5
In Stock
$38
In Stock
Ø25.4 mm 2
In Stock
$38
In Stock
Ø25.4 mm 3
In Stock
$38
In Stock
Ø25.4 mm 4
In Stock
$81
In Stock
50.8 x 50.8 mm 0.04
In Stock
$81
In Stock
50.8 x 50.8 mm 0.1
In Stock
$81
In Stock
50.8 x 50.8 mm 0.15
In Stock
$81
In Stock
50.8 x 50.8 mm 0.2
In Stock
$81
In Stock
50.8 x 50.8 mm 0.3
In Stock
$81
In Stock
50.8 x 50.8 mm 0.4
In Stock
$81
In Stock
50.8 x 50.8 mm 0.5
In Stock
$81
In Stock
50.8 x 50.8 mm 0.6
In Stock
$81
In Stock
50.8 x 50.8 mm 0.7
In Stock
$81
In Stock
50.8 x 50.8 mm 0.8
In Stock
$81
In Stock
50.8 x 50.8 mm 0.9
In Stock
$81
In Stock
50.8 x 50.8 mm 1
In Stock
$81
In Stock
50.8 x 50.8 mm 1.5
In Stock
$81
In Stock
50.8 x 50.8 mm 2
In Stock
$81
In Stock
50.8 x 50.8 mm 3
In Stock
$81
In Stock
50.8 x 50.8 mm 4
In Stock

Specifications

  • Optical Density Tolerance
    ±4% at 546.1 nm
  • Wavelength Range
    400-900 nm
  • Angle of Incidence
  • Wedge
    ≤3 arc min
  • Size Tolerance
    ±0.3 mm
  • Surface Quality
    60-40 scratch-dig
  • Chamfers
    0.25–0.76 mm face width
  • Chamfers Angle Tolerance
    45° ±15°
  • Cleaning
  • Clear Aperture
    ≥central 80% of dimensions
  • Damage Threshold
    30 W/cm2 CW, typical
  • Thickness
    0.99-4.19 mm

Features

Absorptive Neutral Density Glass for Low Power Applications

These neutral density filters are made from absorptive glass. This results in a lower cost product that is somewhat less fragile compared to coated metallic ND filters. Absorptive ND filters also reflect far less light toward the source compared with metallic ND Filters, which may be beneficial. Nevertheless stacking a large number of ND filters can still result in excessive undesired reflection due to Fresnel surface reflection. Due to the absorptive nature of the filter glass, use with high power lasers should be avoided. Power levels less than 30 W/cm2 are advised.

Spectrally Neutral for Visible Wavelengths

Absorptive glass ND filters are spectrally neutral over the visible spectral region. OD05 to OD40 optical densities are shown.

Additive Optical Densities

Optical density (OD) is given by the relationship: OD = -log(T) or T = 10(-OD) where T is transmittance (0≤T≤1). Optical Density, unlike transmittance, is additive. When multiple filters are stacked, the total density is easily found by adding up the densities of each filter in the series. For example to achieve desired transmittance of 8%, first calculate the equivalent density (OD = -log(0.08) = 1.097 ≅ 1.1), then find a combination of filters that adds to the desired number, such as a combination of an OD1 filter and an OD0.1 filter.

Finely Control Beam Attenuation

Our absorptive ND filters are available individually or in a set of 9. Filters may be used individually, or combined in series, to obtain any desired density from 0.04 to 4.0. The Ø25.4 mm and 50.8 mm square sizes are permanently marked with the optical density.

Proper Orientation

To prevent unwanted interference from etalon effects, filters should be angled slightly with respect to the incident beam.

Neutral Density Filter Kit

The FS-3  Absorptive Neutral Density Filter Set includes nine 50.8 x 50.8 mm square absorptive neutral density filters The FS-3R  Absorptive Neutral Density Filter Set is a set of nine 25.4 mm diameter absorptive neutral density filters. Both offer Optical Densities of OD 0.04, 0.2, 0.4, 0.6, 0.8, 1.0, 2.0 and 3.0, which provide broadband attenuation for the visible to NIR region for power levels less than 30 W/cm2. This unique assortment of filters permits easy selection of any desired density from 0 to 8 with 0.1 OD resolution by using individual filters or a combination of no more than two filters. The total filter set range is 0 to 8 OD.