Compare Model Drawings, CAD & Specs Size Optical Density Wavelength Range Material Availability Price
$44
In Stock
Ø25.4 mm 0.04 400-2000 nm Schott Borofloat Glass
In Stock
$44
In Stock
Ø25.4 mm 0.1 400-2000 nm Schott Borofloat Glass
In Stock
$44
In Stock
Ø25.4 mm 0.2 400-2000 nm Schott Borofloat Glass
In Stock
$44
In Stock
Ø25.4 mm 0.3 400-2000 nm Schott Borofloat Glass
In Stock
$44
In Stock
Ø25.4 mm 0.4 400-2000 nm Schott Borofloat Glass
In Stock
$44
In Stock
Ø25.4 mm 0.5 400-2000 nm Schott Borofloat Glass
In Stock
$44
In Stock
Ø25.4 mm 1 400-2000 nm Schott Borofloat Glass
In Stock
$44
In Stock
Ø25.4 mm 1.5 400-2000 nm Schott Borofloat Glass
In Stock
$44
In Stock
Ø25.4 mm 2 400-2000 nm Schott Borofloat Glass
In Stock
$44
In Stock
Ø25.4 mm 2.5 400-2000 nm Schott Borofloat Glass
In Stock
$242
In Stock
Ø25.4 mm
In Stock
$242
In Stock
Ø25.4 mm
In Stock
$389
In Stock
Ø25.4 mm
In Stock

Features

Finely Control Beam Attenuation

Made with Inconel® metallic coatings on glass substrates, these ND filters provide spectrally uniform attenuation over the wavelength range from 0.4 to 2.0 µm. The reflective nature of the coatings helps reduce thermal effects when these filters are used with moderate-power lasers. Filters may be used individually, or combined in series, to obtain any desired density from 0.04 to 2.5.

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.

Proper Orientation

To prevent unwanted interference from etalon effects, filters should be angled slightly with respect to the incident beam. To minimize back reflections, the filter should be oriented with the coated metallic surface facing the incident beam. Any light reflected from the uncoated second surface will pass through the metallic coating first, which will greatly attenuate unwanted back reflections.