Compare Model Drawings, CAD & Specs Size Optical Density Material Availability Price
$811
In Stock
Ø25.4 mm 0.3 Optical grade germanium
In Stock
$811
In Stock
Ø25.4 mm 0.6 Optical grade germanium
In Stock
$811
In Stock
Ø25.4 mm 1 Optical grade germanium
In Stock
$811
In Stock
Ø25.4 mm 2 Optical grade germanium
In Stock
$811
In Stock
Ø25.4 mm 3 Optical grade germanium
In Stock
$414
In Stock
Ø25.0 mm 0.3 Germanium
In Stock
$414
In Stock
Ø25.0 mm 0.5 Germanium
In Stock
$414
In Stock
Ø25.0 mm 1 Germanium
In Stock
$414
In Stock
Ø25.0 mm 2 Germanium
In Stock
$414
In Stock
Ø25.0 mm 3 Germanium
In Stock

Specifications

  • Wavelength Range
    2000-5000 nm
  • Size Tolerance
    ±0.2 mm
  • Thickness
    1.0 mm
  • Thickness Tolerance
    ± 0.2 mm

Features

FIR Series Infrared Filters

FIR filters have a 80-50 scratch dig Germanium substrate and offer higher OD tolerance through the wavelength range. The graph shows that the curve is almost flat over the full wavelength range.

NDIR Series Infrared Filters

NDIR series ND filters feature a 60-40 scratch dig Germanium substrate with looser OD tolerances than the FIR series, but at a good price point.

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.

Filter Kits

The FS-IR Infrared ND Filter Set includes five 25.4 mm diameter filters with optical densities of 0.3, 0.6, 1.0, 2.0 and 3.0. Filter kits provide convenience and cost savings.