Circular Variable Metallic Neutral Density Filters
Circular Variable Metallic Neutral Density Filters
The circular variable ND filters allow users to finely tune the power of a transmitted beam, or to split a beam with an arbitrary power ratio easily by simply rotating the filter.
- Filter OD varies continuously with rotation angle
- Dual purposed as variable beamsplitter
- BK7 and Fused Silica substrate options
- AR coated second surface
- ≤1λ and 30-10 scratch-dig See All Features
| Compare | Description | Drawings, CAD & Specs | Avail. | Price | ||
|---|---|---|---|---|---|---|
 | 50G02AV.1 Circular Variable Metallic ND FiltersND Optical Filter, Circular Variable Metallic, N-BK7, 127 mm, 0.05-1.0 OD | |||||
 | 50G02AV.2 Circular Variable Metallic ND FiltersCircular Variable Metallic ND Filter, N-BK7, 127 mm, 0.05-2.0 OD | Discontinued | ||||
| 50Q04AV.1 Circular Variable Metallic ND FiltersCircular Variable Metallic ND Filter, UV Silica, 127 mm, 0.05-1.0 OD | Discontinued | ||||
 | 50Q04AV.2 Circular Variable Metallic ND FiltersND Optical Filter, Circular Variable Metallic, UV Silica, 127 mm, 0.05-2.0 OD | |||||
Features
Finely Control Beam Attenuation
These filters allow convenient adjustment of beam attenuation by simply rotating the filter. Optical density varies continuously from 0.05–1.0 (or 0.05-2.0) across a 270° angular range. The thin reflective aluminum film is able to withstand moderate power laser beams. BK7 substrates are a good general laboratory use option, while Fused Silica substrates offer maximum thermal stability.
Optimized for 450-700 nm Wavelength Range
Circular variable ND filters are available with BK 7 substrates for general laboratory use, or UV fused silica substrates for maximum thermal stability. Although the coatings are optimized for 450–700 nm, they will operate from 400–1100 nm with only minor losses.
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.
AR Coated Second Surface
The second surface of this circular linear variable filter is AR coated to prevent undesired transmission loss, and to reduce stray light due to back reflections. The AR coating is optimized for 440 to 700 nm.
Circular ND Filter Mounting
Our circular variable attenuators are ideally mounted with our 941 Compact Filter Rotators or 946 (946-M)Tip & Tilt Filter Rotation Mounts.
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.
