UQG Optics

Neutral Density Filters
UQG manufactures two types of neutral density filters. Absorptive glass nd filters and reflective metallic nd filters for the visible/NIR and UV transmitting.
Absorptive Neutral Density Filters
Absorptive Schott glass nd filters are used to control the intensity of light and are stackable without resulting in multiple reflections. The nd glass absorbs the light within the filter. Each glass type is polished to required thickness and measured to produce the exact optical density and transmission. Custom or standard optical density’s and transmission can be produced to a particular wavelength.

Specifications – Standard view stock
Material: Schott ® Filter Glass
Dimensions: Ø +0.00/-0.20mm Squares +/-0.20mm
Thickness: ± 0.10mm
Parallelism: ≤ 3 Arc mins.
Edges: Fine Ground
Flatness: Ø12.5mm ≤ 3 Fringes
Ø25mm ≤ 5 Fringes
50x50mm ≤ 8 Fringes
Surfaces: 60/40
Optical Density: O.D <1.0 ± .05 @ 546nm
O.D > 1.0 ± 5% @546nm


Custom Sizes
Diameters: 5mm to 160mm
Squares/Rectangles: 1mm to 165mm
Thickness: 0.50 to 4.00mm
Dimensions/Thickness: to 0.02mm
Surfaces: 80/50 to 20/10
Flatness: up to Lambda 1
Parallelism: up to 1 min.
Transmission: to 2%
Absorbance: to 0.02mm
Density: To 0.02

Transmission curve 400-1100mm
Absorbance curve 400-1100mm
Calibration certificates
Spot readings @ wavelengths
Identification labels
Storage boxes
Mounts & holders



Reflective Neutral Density Filters
Reflective coated metallic nd filters are coated in two glass types. The visible IR range is nd coated on optical glass to cover 350nm to 2500nm. The UV range is coated on fused silica for use down to 170nm. Please be aware the density’s are coated for 550nm, but in the UV this will give up to 40% higher density.

Specifications – Standard view stock
Material: Optical Glass
Dimensions: Ø 25 + 0.00/-0.20mm 50x50mm +/- 0.20mm
Thickness: 2mm ± 0.20mm
Edges: Fine Ground
Surfaces: 80/50
Coating: Metallic
Spectral Range: 350nm-2500nm
Optical Density: ± 5% @ 550nm


Custom Sizes
Diameters: 5mm to 300mm
Squares/Rectangles: 1mm to 300mm
Thickness: 0.30mm to 6mm

UV transmitting Fused Silica
Transmission curves 400-1100nm
Absorbance curves 400-1100nm
Calibration certificates
Spot reading @ wavelengths
Identification labels
Storage boxes
Mounts & holders


For further information on these products please contact our sales team.