ND Filters: Mounted, AR Coated for 650 - 1050 nm


  • Mounted Ø25 mm Round Filter
  • Optical Densities Ranging from 0.1 to 6.0
  • Ideal for Low-Power Applications (<1 W)

NE40A-B

NE50A-B

Application Idea

NE05A-B Mounted
in a DET36A2 Detector

Related Items


Please Wait
Neutral Density Filter
Selection Guide
Absorptive
Uncoated
(400 - 650 nm)
Mounted
Unmounted
Uncoated
(1000 - 2600 nm)
Mounted
Unmounted
AR Coated
(350 - 700 nm)
Mounted
Unmounted
AR Coated
(650 - 1050 nm)
Mounted
Unmounted
AR Coated
(1050 - 1700 nm)
Mounted
Unmounted
Variable
Reflective
UV Fused Silica
(200 - 1200 nm)
Mounted
Unmounted
N-BK7
(350 - 1100 nm)
Mounted
Unmounted
ZnSe
(2 - 16 µm)
Mounted
Unmounted
Wedged UVFS
(200 - 1200 nm)
Wedged N-BK7
(350 - 1100 nm)
Wedged ZnSe
(2 - 16 µm)
Variable
Neutral Density Filter Kits

Optic Cleaning Tutorial
ND Filter Manufacturing
Click to Enlarge

One of Our Grinding Machines That is Used to Manufacture ND Filters

Features

  • Attenuate Light in the Near IR (650 - 1050 nm AR Coating)
  • Optical Densities Ranging from 0.1 to 6.0
  • Mounted Ø25 mm Filters
  • AR Coated to Reduce Back Reflections in an Optical System
  • Ideal for Low-Power Applications (<1 Watt)
  • Engraved with Coating Range and Part Number

Thorlabs is pleased to offer its most popular mounted absorptive neutral density filters with a broadband antireflection coating for the 650 - 1050 nm range deposited on both surfaces. The high-performance, multilayer broadband B coating deposited on each filter is designed to minimize surface reflections within the 650 - 1050 nm range, thereby reducing the amount of stray light present. These coatings provide an average reflectance that is less than 0.5% over the specified wavelength range when light is normally incident on the filter surface. Typical transmission data may be found by clicking on the blue info icons (info) in the tables below.

These filters are mounted in engraved SM1L03 Ø1" lens tubes, which are compatible with a wide range of rigid optomechanical parts such as our cage systems and lens tubes. If desired, a mounted filter can be removed from its housing by unscrewing the retaining ring that secures the filter to the mount. Thorlabs offers a range of spanner wrenches that are an ideal match to these retaining rings. These filters are also available unmounted. The equivalent unmounted filter is listed in the drawing for each mounted filter, accessible through the red docs icons () below. Please see the Selection Guide table to the right for all neutral density filter options.

Unlike metallic neutral density filters, each absorptive ND filter is fabricated from one member of a family of Schott glasses (see the Specs tab for more information). Each Schott glass has a spectrally flat absorption coefficient. By varying the type of glass used and the thickness of that glass, we are able to produce our entire line of absorptive ND filters from just four types of Schott glass. See below for detailed information about the average transmission obtained with each of our AR-coated absorptive neutral density filters.

Optical Density and Transmission
Optical density (OD) indicates the attenuation factor provided by an optical filter, i.e. how much it reduces the optical power of an incident beam. OD is related to the transmission, T, by the equation

Optical Density Equation

where T is a value between 0 and 1. Choosing an ND filter with a higher optical density will translate to lower transmission and greater absorption of the incident light. For higher transmission and less absorption, a lower optical density would be appropriate. As an example, if a filter with an OD of 2 results in a transmission value of 0.01, this means the filter attenuates the beam to 1% of the incident power. Please note that the transmission data for our neutral density filters is provided in percent (%).

Please note that these products are not designed for use as laser safety equipment. For lab safety, Thorlabs offers an extensive line of safety and blackout products, including beam blocks, that significantly reduce exposure to stray light.

Transmission and Optical Density of -B Coated ND Filters. The values in the legend are the typical optical densities at 633 nm for each optic prior to coating. The blue shaded region indicates the wavelength range for which the AR coating performance is specified.
Optical Density (OD)a OD Tolerancea Substrate Substrate Thicknessb
0.1 ±0.01 NG11 0.6 mm
0.2 ±0.01 NG11 1.4 mm
0.3 ±0.015 NG11 2.3 mm
0.4 ±0.02 NG4 0.7 mm
0.5 ±0.025 NG4 0.9 mm
0.6 ±0.03 NG4 1.1 mm
0.7 ±0.04 NG4 1.3 mm
0.8 ±0.05 NG4 1.5 mm
0.9 ±0.05 NG4 1.7 mm
1.0 ±0.05 NG4 1.9 mm
1.3 ±0.065 NG4 2.5 mm
1.5 ±0.08 NG4 2.9 mm
2.0 ±0.1 NG9 1.4 mm
3.0 ±0.15 NG9 2.1 mm
4.0 ±0.2 NG9 2.8 mm
5.0 ±0.25 NG9 3.6 mm
6.0 ±0.3 NG1 1.5 mm
  • Measured at 633 nm before the AR coating was applied.
  • Values given are typical. The actual thickness of each ND filter is dependent on the optical density of the lot of glass used to manufacture each lot of ND filters.
General Specifications
Diameter 25.0 mm
Diameter Tolerance +0.00 / -0.25 mm
Clear Aperture >Ø20.0 mm
AR Coating Range 650 - 1050 nm
Reflectance (Average) <0.5% per Surfacea
Surface Quality 60-40 Scratch-Dig
Transmitted Wavefront Error (TWE) <λ/4 (@ 633 nm)
  • At 0° AOI
B AR Coating
Click to Enlarge

Click Here for Raw Data
The blue shaded region indicates the 650 - 1050 nm wavelength range over which the AR coating provides <0.5% average reflectance per surface.

Posted Comments:
Tom de Rooij  (posted 2022-07-14 14:38:10.763)
Dear sir/madam, I have a question about the set of absorptive AR coated Neutral Density Filters, specifically considering the damage threshold. The filters are mentioned as ideal for low power applications. Could you give an indication of the damage threshold in terms of W/cm^2? I couldn't find it easily in the specifications. Best, Tom de Rooij
cdolbashian  (posted 2022-07-26 03:30:16.0)
Thank you for reaching out to us Tom. I have contacted you directly to discuss the damage threshold in terms of your specific light source. We have not done extensive testing for the damage threshold of these optics yet.
user  (posted 2019-08-02 10:56:09.283)
What are the damage thresholds?
YLohia  (posted 2019-08-02 11:38:26.0)
Hello, thank you for contacting Thorlabs. Unfortunately, we have not yet performed conclusive damage threshold tests for these optics. These optics are intended for < 1 W beams. That being said, damage thresholds are quite dependent on specific beam parameters such as wavelength, diameter, and average power (peak power, pulse width, rep rate, pulse energy, if applicable). If you would like to find out about the suitability of a particular optic for your application, please email techsupport@thorlabs.com with these parameters.
Back to Top

Ø25 mm Mounted Absorptive ND Filters, AR-Coated: 650 - 1050 nm

Item # Transmissiona ODb Thicknessc
NE10A-B info 1.0 ± 0.05 1.9 mm
NE13A-B info 1.3 ± 0.065 2.5 mm
NE15A-B info 1.5 ± 0.08 2.9 mm
NE20A-B info 2.0 ± 0.1 1.4 mm
NE30A-B info 3.0 ± 0.15 2.1 mm
NE40A-B info 4.0 ± 0.2 2.8 mm
NE50A-B info 5.0 ± 0.25 3.6 mm
NE60A-B info 6.0 ± 0.3 1.5 mm
Item # Transmissiona ODb Thicknessc
NE01A-B info 0.1 ± 0.01 0.6 mm
NE02A-B info 0.2 ± 0.01 1.4 mm
NE03A-B info 0.3 ± 0.015 2.3 mm
NE04A-B info 0.4 ± 0.02 0.7 mm
NE05A-B info 0.5 ± 0.025 0.9 mm
NE06A-B info 0.6 ± 0.03 1.1 mm
NE07A-B info 0.7 ± 0.04 1.3 mm
NE08A-B info 0.8 ± 0.05 1.5 mm
NE09A-B info 0.9 ± 0.05 1.7 mm
  • Click the blue icon to view a plot of the transmission.
  • Measured at 633 nm before the AR coating was applied.
  • Values given are typical. The actual thickness of each ND filter is dependent on the optical density of the lot of glass used to manufacture each lot of ND filters.
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
NE01A-B Support Documentation
NE01A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 0.1
$86.75
Today
NE02A-B Support Documentation
NE02A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 0.2
$86.75
Today
NE03A-B Support Documentation
NE03A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 0.3
$89.96
Today
NE04A-B Support Documentation
NE04A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 0.4
$86.75
Today
NE05A-B Support Documentation
NE05A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 0.5
$86.75
Today
NE06A-B Support Documentation
NE06A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 0.6
$86.75
Today
NE07A-B Support Documentation
NE07A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 0.7
$86.75
Today
NE08A-B Support Documentation
NE08A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 0.8
$86.75
Today
NE09A-B Support Documentation
NE09A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 0.9
$86.75
Today
NE10A-B Support Documentation
NE10A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD:1.0
$89.96
Today
NE13A-B Support Documentation
NE13A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 1.3
$86.75
Today
NE15A-B Support Documentation
NE15A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 1.5
$86.75
Today
NE20A-B Support Documentation
NE20A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 2.0
$89.96
Today
NE30A-B Support Documentation
NE30A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 3.0
$86.75
Today
NE40A-B Support Documentation
NE40A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 4.0
$86.75
Today
NE50A-B Support Documentation
NE50A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 5.0
$86.75
Today
NE60A-B Support Documentation
NE60A-BØ25 mm Absorptive Neutral Density Filter, ARC: 650-1050 nm, SM1-Threaded Mount, OD: 6.0
$86.75
Today