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Features

• Available in Four Sizes:
  • Round: 1/2", 1", and 2"
  • Square: 100 mm x 100 mm
• Substrate Material: N-BK7 (Uncoated)

Thorlabs' Unmounted N-BK7 Ground Glass Diffusers provide a solution for 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 1/2", 1", and 2" round sizes as well as 100 mm x 100 mm square version. For improved transmission, our Ø1" diffusers are also available with either an AR coating for 350 - 700 nm or 650 - 1050 nm. 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.

Build Your Own Collimated LED Source

The setup shown to the right uses a custom 2" x 2", square, 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 MWWHL3 mounted warm white light 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 custom ground glass diffuser, which is held in place using an LCP05 Cage-Compatible Mount for 2" Square Filters. After exiting the diffuser, the divergent light is collimated using an LA1401 Ø2" Uncoated Plano-Convex Lens with a focal length of 60.0 mm. The lens is 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 LCP05, placed in a PH3 post holder, and attached to the breadboard using a BA2 Mounting base.