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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 Gaussian diffusers. They are offered in 120, 220, 600, and 1500 grit polishes. Each grit polish is available in Ø1/2", Ø1", and Ø2" sizes, 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 the surface has greater uniformity. The various grits provide a range from fine to coarse scattering. A finer grit (e.g., 1500) allows higher transmission, while a coarser grit (e.g., 120) creates a wider diffusion pattern at the expense of transmission. Please see the graph above to compare the performance of our ground glass diffusers.

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

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Measured at 633 nm
Click here to download the data.

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.

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Click for Raw Data

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Click for Raw Data

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Click for Raw Data

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Build Your Own Collimated LED Source

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.