Metallic ND Filter, UV Fused Silica, 25.4 mm, 0.4 OD at 632.8 nm

UV Fused Silica Metallic ND Filters

The FRQ-ND04 UV Fused Silica Metallic Neutral Density Filter is a 25.4 mm diameter UV Fused Silica Metallic ND Filter with an optical density of 0.4 at 632.8 nm. 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 near-infrared. All filters are permanently marked with the optical density.

Specifications

Technical Specs

Size
Ø25.4 mm
Wavelength Range
200 - 1800 nm
Optical Density
0.4
Optical Density Tolerance
±5% @ 632.8 nm
Transmission
39.8% @ 632.8 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
Size Tolerance
±0.25 mm
Thickness
3.0 mm
Thickness Tolerance
±0.25 mm

Surface Flatness
≤1λ at 632.8 nm over the clear aperture
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

Size
Ø25.4 mm
Wavelength Range
200 - 1800 nm
Optical Density
0.4
Optical Density Tolerance
±5% @ 632.8 nm
Transmission
39.8% @ 632.8 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
Size Tolerance
±0.25 mm
Thickness
3.0 mm
Thickness Tolerance
±0.25 mm

Surface Flatness
≤1λ at 632.8 nm over the clear aperture
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

Resources & Downloads

2D Product Drawings

FBR-NDXX-S(62 kB, PDF)

Other

FRQ-ND04 RoHS Certificate(265 kB, PDF)
FRQ-ND04_ROHS2-2021.pdf(280.7 kB, PDF)

Related Products

Similar

	Compare	Description	Compatibility	Drawings, CAD & Specs	Avail.	Price
		FRQ-ND10Metallic ND Filter, UV Fused Silica, 25.4 mm, 1.0 OD at 632.8 nm	UNIVERSAL		In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$73
		FBR-ND04ND Filter, Metallic, Optical Crown Glass, 25.4 mm, 0.4 OD at 632.8 nm	UNIVERSAL		In Stock	$61
		5234NFNeutral Density Filter, 0.4 Optical Density, 1.0 in. Diameter	UNIVERSAL		In Stock	$47
		FSR-OD40Neutral Density Filter, Absorptive, 25.4 mm, 0.4 OD at 546.1 nm	UNIVERSAL		In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$41

Compatible

	Compare	Description	Compatibility	Drawings, CAD & Specs	Avail.	Price
		FH-1SOptical Filter Holder, Drop-in, 25.4 mm Optics	UNIVERSAL		In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$89
		FH-1ROptical Filter Mount, Stackable, 1.0 in. Diameter Optics	UNIVERSAL		In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$43

Frequently Purchased Together

	Compare	Description	Compatibility	Drawings, CAD & Specs	Avail.	Price
		FRQ-ND10Metallic ND Filter, UV Fused Silica, 25.4 mm, 1.0 OD at 632.8 nm	UNIVERSAL		In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$73
		FRQ-ND02Metallic ND Filter, UV Fused Silica, 25.4 mm, 0.2 OD at 632.8 nm	UNIVERSAL		In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$73
		FRQ-ND01Metallic ND Filter, UV Fused Silica, 25.4 mm, 0.1 OD at 632.8 nm	UNIVERSAL		In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$73