Compare Model Drawings, CAD & Specs Size Optical Density Availability Price
100FS01DV.1
$482
In Stock
 100FS01DV.1 Ø100.0 mm 0 - 1
In Stock
 $482
100FS02DV.2
$482
In Stock
 100FS02DV.2 Ø100.0 mm 0 - 2
In Stock
 $482
100FS04DV.4
$513
In Stock
 100FS04DV.4 Ø100.0 mm 0 - 4
In Stock
 $513
25FS01DV.1
$286
In Stock
 25FS01DV.1 Ø25.0 mm 0 - 1
In Stock
 $286
25FS02DV.2
$286
In Stock
 25FS02DV.2 Ø25.0 mm 0 - 2
In Stock
 $286
25FS04DV.4
$308
In Stock
 25FS04DV.4 Ø25.0 mm 0 - 4
In Stock
 $308
50FS01DV.1
$392
In Stock
 50FS01DV.1 Ø50.0 mm 0 - 1
In Stock
 $392
50FS02DV.2
$392
In Stock
 50FS02DV.2 Ø50.0 mm 0 - 2
In Stock
 $392
50FS04DV.4
$414
In Stock
 50FS04DV.4 Ø50.0 mm 0 - 4
In Stock
 $414

Specifications

  • Wavelength Range
    250-2500 nm
  • Material
    Fused silica
  • Size Tolerance
    +0/-0.3 mm
  • Thickness
    2.0 mm
  • Thickness Tolerance
    ±0.25 mm
  • Surface Flatness
    2λ
  • Surface Quality
    80-50 scratch-dig
  • Wedge
    ≤ 20 arc sec
  • Chamfers
    0.2-0.3 mm face width
  • Chamfers Angle Tolerance
    45° ±15°
  • Durability
    Metalized area MIL-M-13508C, AR coated area MIL-C-675, moderate abrasion
  • Inside Diameter
    7.5 mm
  • Cleaning
    See How to Clean Optics

Features

Finely Control Beam Attenuation

These variable neutral density filters allow convenient adjustment of beam attenuation by simply rotating the filter. Optical density varies linearly with rotation angle across a 270° range from 0 up to the chosen maximum of OD1, OD2, or OD4. An arbitrary transmitted beam power may then be obtained easily using the angular markings to rotating the variable ND filter to the specific corresponding angle. Due to this linearity in density, the rotation may even be motorized to produce a precise logarithmic sweep in the transmitted beam power.

Wide Wavelength Range

Fused silica substrate for these ND filters allows the transparency from 250-2500 nm range.

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.

Variable Beamsplitter Applications

These filters consist of a thin metallic coating of variable thickness. Because attenuation is primarily caused by reflection with only a small amount of absorption, these filters may optionally be used as variable beamsplitters.

Filter Mounting

We offer a variety of rotary mounts for the variable neutral density filter. Please check out the accessories section below for recommendations. Shown is model FR-CV-75 compact circular variable ND filter mount.