Mounted N-BK7 Ground Glass Diffusers


  • Offered in 120, 220, 600, and 1500 Grit Polishes
  • Polished for Greater Uniformity than Sand Blasting
  • Available in SM05-, SM1-, and SM2-Threaded Mounts

DGK01

DG05-220-MD

DG20-220-MD

Diffused
LED Condenser

Application Idea

Related Items


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Features

  • Three Sizes Available:
    • Ø1/2" Diffuser in an SM05-Threaded (0.535"-40) Mount
    • Ø1" Diffuser in an SM1-Threaded (1.035"-40) Mount
    • Ø2" Diffuser in an SM2-Threaded (2.035"-40) Mount
  • Substrate Material: N-BK7 (Uncoated)

Thorlabs' Mounted N-BK7 Ground Glass Diffusers can be used in a variety of applications requiring a diffuse Gaussian-like distribution. They are offered in 120, 220, 600, and 1500 grit polishes. Each grit polish is available in Ø1/2", Ø1", and Ø2" versions, housed in SM05-, SM1-, and SM2-threaded mounts, respectively. Each SM-threaded mount is engraved with the item number, the diameter size, and the grit. When positioning the diffusers, the grit-polished side should face away from the source.

Polished diffusers are advantageous over sand blasted diffusers, as their surfaces have greater uniformity. The various grits provide a range from fine to coarse scattering. A finer grit (e.g. 1500) has a small diffusion pattern, while a coarser grit (e.g. 120) will have a larger diffuser pattern. See the plot below to compare the performance of our diffusers. See the Graphs tab to see individual graphs for each grit polish level, as well as measurement details.

Click to Enlarge
Click to Download Raw Data
See the Graphs Tab for Information about BSDF Measurement

Please see the Application Idea tab for a Diffused LED Condenser that uses a ground glass diffuser. For applications requiring specific divergence angles, spatial distribution of the illumination, and intensity profiles, our engineered diffusers are more suitable. Thorlabs also offers UV Fused Silica Diffusers for applications that extend into the ultraviolet portion of the spectrum.

Diffuser Selection Guide
Ground Glass Diffusers
Standard Diffusers N-BK7 Substrate Unmounted, Uncoated 350 nm to 2.0 µm
Unmounted, AR-Coated 350 nm - 700 nm
650 nm - 1050 nm
Mounted, Uncoated 350 nm - 2.0 µm
UVFS Substrate Unmounted, Uncoated 185 nm - 2.0 µm
Diffuse Reflectors N-BK7 Substrate Unmounted, UV-Enhanced Aluminum Coated 250 nm - 450 nm
Unmounted, Protected Silver Coated 450 nm - 20 µm
Unmounted, Protected Gold Coated 800 nm - 20 µm
Alignment Disks
Engineered Diffusers
Diffuser Kits
Common Specifications 
Diffuser Thickness 2.0 mm
Clear Aperture >90%
Surface Flatness of Smooth Side (@ 633 nm) <4λ
Surface Quality of Smooth Side 80-50 Scratch-Dig
Parallelism <3 arcmin
Item # Size Grit
DG05-120-MD Ø1/2" 120
DG05-220-MD Ø1/2" 220
DG05-600-MD Ø1/2" 600
DG05-1500-MD Ø1/2" 1500
DG10-120-MD Ø1" 120
DG10-220-MD Ø1" 220
DG10-600-MD  Ø1" 600
DG10-1500-MD Ø1" 1500
DG20-120-MD  Ø2" 120
DG20-220-MD Ø2" 220
DG20-600-MD  Ø2" 600
DG20-1500-MD  Ø2" 1500

Please note that the transmission values are affected by the manner in which the data is collected. An integrating sphere is used along with a spectrometer, and as the grit values get smaller the light is more dispersed, making it difficult to collect all of the light into the spectrometer. Therefore, lower grit values will appear to have a lower transmission.


Bidirectional Scattering Distribution Function Graphs

This data was taken by directing a HeNe laser at a diffuser and collecting the light with a receiver that was rotated around the diffuser to measure the angle-resolved scatter (ARS). The bidirectional scattering distribution function (BSDF), which is found by dividing the ARS by the cosine of the angle between the input beam and the receiver, measures the amount of scattering that occurs after light permeates the diffuser. The X axis of these graphs is the angle at which the scatter is occurring. This is why at 0° there can be a spike; this spike is representative of the specular beam going through the diffuser.

Build Your Own Collimated LED Source

LCP05 Application Idea

The setup shown to the right uses a DG20-600-MD, Ø2", 600 Grit Ground Glass Diffuser as part of a homemade Diffused LED Condenser, which collimates the light exiting the LED source. Although Thorlabs also manufactures out-of-the-box collimated LED light sources, which essentially provide the same result, the one shown here is perfect for those inclined to build their own, perhaps as part of an educational setup. In this particular case, the setup was built using a 60 mm cage system. If you are not familiar with Thorlabs' 60 mm cage assemblies, they consist of cage-compatible components that are interconnected with cage rods. Each cage component features four tapped holes with center-to-center spacings of 60 mm, and they are joined together into a cage system using Ø6 mm rigid steel cage rods; in this case, 4" long cage assembly rods were chosen. The reason for building a cage system is to ensure that the optical components housed inside the cage system have a common optical axis.

To integrate the MWWHL4 Warm White Mounted LED, which has internal SM1 (1.035"-40) threading, into the 60 mm cage system, the mounted LED was threaded into an LCP02 30 mm-to-60 mm cage plate adapter using an SM1T2 Lens Tube Coupler. Next, the light source is directed through a Ø2", 600 grit ground glass diffuser, which is mounted using an LCP01 60 mm Cage Plate. After exiting the diffuser, the divergent light is collimated using an LA1401 Plano Convex Lens with a focal length of 60.0 mm. The lens is also housed in an LCP01 60 mm Cage Plate.

The entire 60 mm cage assembly is mounted onto a TR3 post using the 8-32 thread on the bottom of the LCP01, placed in a PH3 post holder, and attached to the breadboard using a BA2 Mounting base.

Component Items Needed to Build a Diffused LED Condenser
Item# Description Qty.
MWWHL4a 3000 K, 570 mW (Min) Mounted LED, 1000 mA 1
LCP02 30 mm to 60 mm Cage Plate Adapter 1
SM1T2 SM1 (1.035"-40) Coupler, External Threads 1
LCP01 60 mm Threaded Cage Plate
(Two SM2RR Retaining Rings Included)
2
DG20-600-MD Ø2", SM2-Mounted N-BK7 Ground Glass Diffuser, 600 Grit 1
ER4 Cage Assembly Rod, 4" Long, Ø6 mm 4
LA1401 N-BK7 Uncoated Plano-Convex Lens, Ø50.8 mm, f = 60.0 mm 1
TR3 Ø1/2" x 3" Post 1
PH3 Post Holder with Spring-Loaded Thumbscrew, L=3" 1
BA2 Mounting Base, 2" x 3" x 3/8" (51 x 76 x 10 mm) 1
  • If you do not currently own an LEDD1B T-Cube­™ LED Driver (or any other industry standard driver with a circular 4-pin M8 connector), you will need to also purchase one of these, as well as a power supply.

Posted Comments:
Łukasz Gryko  (posted 2020-01-03 07:26:11.433)
Is it possible to obtain the parameters BTDF A, BTDF A and BTDFg of these diffusers: 120 grit 220 grit 600 grit 1500 grit ?
YLohia  (posted 2020-01-23 04:37:10.0)
Hello, I have reached out to you directly to gather more information about the parameters that you're looking for.

Ø1/2" N-BK7 Ground Glass Diffusers

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
DG05-120-MD Support Documentation
DG05-120-MDØ1/2", SM05-Mounted N-BK7 Ground Glass Diffuser, 120 Grit
$29.41
Today
DG05-220-MD Support Documentation
DG05-220-MDØ1/2", SM05-Mounted N-BK7 Ground Glass Diffuser, 220 Grit
$29.41
Today
DG05-600-MD Support Documentation
DG05-600-MDØ1/2", SM05-Mounted N-BK7 Ground Glass Diffuser, 600 Grit
$29.41
Today
DG05-1500-MD Support Documentation
DG05-1500-MDØ1/2", SM05-Mounted N-BK7 Ground Glass Diffuser, 1500 Grit
$29.41
7-10 Days

Ø1" N-BK7 Ground Glass Diffusers

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
DG10-120-MD Support Documentation
DG10-120-MDØ1", SM1-Mounted N-BK7 Ground Glass Diffuser, 120 Grit
$32.61
Today
DG10-220-MD Support Documentation
DG10-220-MDØ1", SM1-Mounted N-BK7 Ground Glass Diffuser, 220 Grit
$33.77
Today
DG10-600-MD Support Documentation
DG10-600-MDØ1", SM1-Mounted N-BK7 Ground Glass Diffuser, 600 Grit
$33.77
Today
DG10-1500-MD Support Documentation
DG10-1500-MDØ1", SM1-Mounted N-BK7 Ground Glass Diffuser, 1500 Grit
$33.77
7-10 Days

Ø2" N-BK7 Ground Glass Diffusers

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
DG20-120-MD Support Documentation
DG20-120-MDØ2", SM2-Mounted N-BK7 Ground Glass Diffuser, 120 Grit
$43.97
Today
DG20-220-MD Support Documentation
DG20-220-MDØ2", SM2-Mounted N-BK7 Ground Glass Diffuser, 220 Grit
$43.97
Today
DG20-600-MD Support Documentation
DG20-600-MDØ2", SM2-Mounted N-BK7 Ground Glass Diffuser, 600 Grit
$43.97
Today
DG20-1500-MD Support Documentation
DG20-1500-MDØ2", SM2-Mounted N-BK7 Ground Glass Diffuser, 1500 Grit
$43.97
Today

Mounted Diffuser Kit, Ø1"

DGK01 Contents
Item # Description
DG10-120-MD Ø1", SM1-Mounted N-BK7 Ground Glass Diffuser, 120 Grit
DG10-220-MD Ø1", SM1-Mounted N-BK7 Ground Glass Diffuser, 220 Grit
DG10-600-MD Ø1", SM1-Mounted N-BK7 Ground Glass Diffuser, 600 Grit
DG10-1500-MD Ø1", SM1-Mounted N-BK7 Ground Glass Diffuser, 1500 Grit
DG10-1500-H1-MD Ø1", SM1-Mounted Ground Glass Alignment Disk, 1500 Grit

The DGK01 diffuser kit includes four Ø1" mounted ground glass diffusers, a Ø1" mounted ground glass alignment disk, and a plastic storage box. The SM1-threaded mounts are engraved with the item number and a brief item description.

Please see the table to the right for the contents of this diffuser kit. The table below contains specifications for the alignment disk DG10-1500-H1-MD.

Alignment Disk Specifications
Optic Diameter Ø25.4 mm (Ø1")
Optic Thickness 2.0 mm (0.079")
Center Hole Diameter Ø1 mm (Ø0.04")
Grit 1500
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
DGK01 Support Documentation
DGK01Ø1", SM1-Mounted N-BK7 Ground Glass Diffuser Kit, 5 Pieces
$244.58
Today