Compare Model Drawings, CAD & Specs Size Optical Density Optical Density Tolerance Availability Price
FRQ-ND003
$45
In Stock
 FRQ-ND003 Ø25.4 mm 0.03 ±2.5% @ 632.8 nm
In Stock
 $45
FRQ-ND01
$71
In Stock
 FRQ-ND01 Ø25.4 mm 0.1 ±8% @ 632.8 nm
In Stock
 $71
FRQ-ND02
$71
In Stock
 FRQ-ND02 Ø25.4 mm 0.2 ±7% @ 632.8 nm
In Stock
 $71
FRQ-ND03
$71
In Stock
 FRQ-ND03 Ø25.4 mm 0.3 ±6% @ 632.8 nm
In Stock
 $71
FRQ-ND04
$71
In Stock
 FRQ-ND04 Ø25.4 mm 0.4 ±5% @ 632.8 nm
In Stock
 $71
FRQ-ND05
$71
4 Weeks
 FRQ-ND05 Ø25.4 mm 0.5 ±4% @ 632.8 nm
4 Weeks
 $71
FRQ-ND06
$79
In Stock
 FRQ-ND06 Ø25.4 mm 0.6 ±4% @ 632.8 nm
In Stock
 $79
FRQ-ND07
$79
In Stock
 FRQ-ND07 Ø25.4 mm 0.7 ±4% @ 632.8 nm
In Stock
 $79
FRQ-ND08
$79
In Stock
 FRQ-ND08 Ø25.4 mm 0.8 ±4% @ 632.8 nm
In Stock
 $79
FRQ-ND09
$79
In Stock
 FRQ-ND09 Ø25.4 mm 0.9 ±4% @ 632.8 nm
In Stock
 $79
FRQ-ND10
$71
In Stock
 FRQ-ND10 Ø25.4 mm 1 ±4% @ 632.8 nm
In Stock
 $71
FRQ-ND15
$71
In Stock
 FRQ-ND15 Ø25.4 mm 1.5 ±4% @ 632.8 nm
In Stock
 $71
FRQ-ND20
$71
2 Weeks
 FRQ-ND20 Ø25.4 mm 2 ±4% @ 632.8 nm
2 Weeks
 $71
FRQ-ND25
$71
In Stock
 FRQ-ND25 Ø25.4 mm 2.5 ±4% @ 632.8 nm
In Stock
 $71
FRQ-ND30
$71
In Stock
 FRQ-ND30 Ø25.4 mm 3 ±4% @ 632.8 nm
In Stock
 $71
FRQ-ND40
$79
In Stock
 FRQ-ND40 Ø25.4 mm 4 ±4% @ 632.8 nm
In Stock
 $79
FSQ-ND003
$133
In Stock
 FSQ-ND003 50.8 x 50.8 mm 0.03 ±2.5% @ 632.8 nm
In Stock
 $133
FSQ-ND01
$144
In Stock
 FSQ-ND01 50.8 x 50.8 mm 0.1 ±8% @ 632.8 nm
In Stock
 $144
FSQ-ND02
$151
In Stock
 FSQ-ND02 50.8 x 50.8 mm 0.2 ±7% @ 632.8 nm
In Stock
 $151
FSQ-ND03
$158
In Stock
 FSQ-ND03 50.8 x 50.8 mm 0.3 ±6% @ 632.8 nm
In Stock
 $158
FSQ-ND04
$158
In Stock
 FSQ-ND04 50.8 x 50.8 mm 0.4 ±5% @ 632.8 nm
In Stock
 $158
FSQ-ND05
$158
In Stock
 FSQ-ND05 50.8 x 50.8 mm 0.5 ±4% @ 632.8 nm
In Stock
 $158
FSQ-ND06
$158
2 Weeks
 FSQ-ND06 50.8 x 50.8 mm 0.6 ±4% @ 632.8 nm
2 Weeks
 $158
FSQ-ND07
$158
In Stock
 FSQ-ND07 50.8 x 50.8 mm 0.7 ±4% @ 632.8 nm
In Stock
 $158
FSQ-ND08
$158
In Stock
 FSQ-ND08 50.8 x 50.8 mm 0.8 ±4% @ 632.8 nm
In Stock
 $158
FSQ-ND09
$158
In Stock
 FSQ-ND09 50.8 x 50.8 mm 0.9 ±4% @ 632.8 nm
In Stock
 $158
FSQ-ND10
$158
In Stock
 FSQ-ND10 50.8 x 50.8 mm 1 ±4% @ 632.8 nm
In Stock
 $158
FSQ-ND15
$158
In Stock
 FSQ-ND15 50.8 x 50.8 mm 1.5 ±4% @ 632.8 nm
In Stock
 $158
FSQ-ND20
$165
In Stock
 FSQ-ND20 50.8 x 50.8 mm 2 ±4% @ 632.8 nm
In Stock
 $165
FSQ-ND25
$165
In Stock
 FSQ-ND25 50.8 x 50.8 mm 2.5 ±4% @ 632.8 nm
In Stock
 $165
FSQ-ND30
$165
In Stock
 FSQ-ND30 50.8 x 50.8 mm 3 ±4% @ 632.8 nm
In Stock
 $165
FSQ-ND40
$165
3 Weeks
 FSQ-ND40 50.8 x 50.8 mm 4 ±4% @ 632.8 nm
3 Weeks
 $165

Specifications

  • Wavelength Range
    350 - 2000 nm
  • Angle of Incidence
    0°
  • Material
    UV grade fused silica or equivalent
  • Damage Threshold
    30 W/cm2 CW, typical; not recommended for pulsed laser use
  • Thickness
    3.0 mm
  • Thickness Tolerance
    ±0.25 mm
  • Surface Quality
    60-40 scratch-dig
  • Clear Aperture
    ≥central 80% of dimensions
  • Wedge
    ≤3 arc min
  • Chamfers
    0.25–0.76 mm face width
  • Chamfers Angle Tolerance
    45° ±15°
  • Durability
    MIL-C-48497A, adhesion, humidity, moderate abrasion, and solubility requirements
  • Cleaning
    See How to Clean Optics

Features

Finely Control Beam Attenuation

These filters are available individually or in a set of eight. The set consists of a logical assortment of filters packaged in a protective hardwood case. All filters are permanently marked with the optical density and are shipped with a transmission curve. Filters from this product family may be used individually, or combined in series, to obtain any desired density from 0 to 7 in steps of 0.1 OD.

Typical curve. Actual transmission may vary.

Metallic Coating Properties

Due to the absorptive nature of the metallic coating, use with high-power lasers should be avoided. Power levels less than 30 W/cm2 are advised.

For additional attenuators, see Laser Beam Attenuators

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.

UV Fused Silica Substrate

The coating is deposited on one side of an ultra-pure UV grade fused silica substrate providing excellent transmission from the ultraviolet to the near-infrared (350-2000nm). These precision polished substrates have flatness less than 1λ–2λ, resulting in low wavefront distortion for the transmitted beam. The polished second surface is uncoated.

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.

Neutral Density Filter Kits

The FR-ND UV Fused Silica Metallic Neutral Density Filter Set includes eight, 25.4 mm diameter, UV Fused Silica Metallic ND Filters. The FS-ND UV Fused Silica Metallic Neutral Density Filter Set includes eight, 50.8 x 50.8 mm square, UV Fused Silica Metallic ND Filters. Each kit includes optical densities of 0.03, 0.1, 0.3, 0.5, 1.0, 2.0 and 3.0. Our metallic neutral density coatings provide broadband attenuation for lower power applications. The coating is deposited on one side of an ultra-pure UV grade fused silica substrate providing excellent transmission from the UV to NIR. Filter kits provide convenience and cost savings.