UV Fused Silica Ground Glass Diffusers

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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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Features

Ø1" Round Diffusers
UV Fused Silica Substrate
Greater than 90% Transmission Above 225 nm
Gaussian Spatial Profile
Clear Aperture: >90% Diameter

Thorlabs' UV Fused Silica Ground Glass Diffusers produce a Gaussian intensity profile from an input light source. Unlike our diffusers based on N-BK7 substrates, UV fused silica is highly transmissive at wavelengths below 350 nm. In addition, UV fused silica exhibits virtually no laser-induced fluorescence (as measured at 193 nm), making it an ideal choice for applications in a range spanning the ultraviolet to the near infrared. See the Comparison tab for a side-by-side comparison of the wavelength-dependent transmission of N-BK7 and UV fused silica.

These diffusers feature 120, 220, 600, or 1500 grit polishes. Our polishing process results in a surface with significantly greater uniformity than sandblasted diffusers. 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 to the right to compare the performance of our diffusers and the Graphs tab to see the transmission through the diffusers.

When mounting the diffusers, the grit polished side should face away from the source. Thorlabs offers fixed lens mounts to hold these diffusers.

If transmission in the ultraviolet range is not necessary for your application, please consider our line of N-BK7 Ground Glass Diffusers.

Common Specifications
Diameter	1.00"
Diameter Tolerance	+0.00/-0.25 mm
Thickness	2.0 mm
Thickness Tolerance	±0.2 mm
Clear Aperture	>90% Diameter
Surface Flatness of Smooth Side (@ 633 nm)	<λ
Surface Quality of Smooth Side	80-50 Scratch-Dig
Parallelism	<3 arcmin

Item #	Grit
DGUV10-120	120
DGUV10-220	220
DGUV10-600	600
DGUV10-1500	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.

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Comparison of N-BK7 and UV Fused Silica

N-BK7 is a popular substrate because of its low cost and excellent transmission in the visible and near-infrared portions of the spectrum. However, its transmission drops off sharply at wavelengths shorter than 350 nm. For applications in the ultraviolet portion of the spectrum, UV fused silica is a superior alternative. UV fused silica offers high transmission deep into the ultraviolet, good homogeneity, and a lower coefficient of thermal expansion than N-BK7. In addition, UV fused silica exhibits virtually no laser-induced fluorescence (as measured at 193 nm), making it an ideal choice for applications from the UV to the near IR. See the graph to the right for a comparison between N-BK7 and UV fused silica.

Thorlabs also offers N-BK7 Ground Glass Diffusers for applications where UV transmission is not a requirement.

Posted Comments:

Jordan Rabinowitz (posted 2020-08-20 10:34:29.96)

Hello, I have questions about the plot on your website for the normalized power vs angle from the diffuser. What wavelength was this measurement taken with? We have a 1064nm laser and need to know if the power vs angle plot will be significantly different. If possible, can you also send me the raw data from this plot? Thank you

YLohia (posted 2020-09-04 10:03:02.0)

Hello, thank you for contacting Thorlabs. These measurements were taken at 635 nm. We don't expect to see a significantly deviating performance at 1064 nm. We will reach out directly with the raw data.

yuheng jiang (posted 2020-08-12 20:06:13.54)

Excuse me, is there a damage threshold for each diffuser? our laser is @266nm 10Hz. Thank you!

nbayconich (posted 2020-08-13 03:16:12.0)

Thank you for contacting Thorlabs. We have not performed official laser damage threshold testing for our UVFS ground glass diffusers, however being that the surfaces are ground and not polished as our windows are, the theoretical damage threshold for UVFS diffusers would be lower than that of a UVFS polished window. I will reach out to you directly.

Cheng Xu (posted 2020-02-06 19:53:33.753)

Hi , could you send me the BSDF data of the above product? Best, Cheng

nbayconich (posted 2020-02-11 11:00:23.0)

Thank you for contacting Thorlabs. We do not have BSDF data for these diffusers at the moment however we do have a transmission plot vs. output angle plot on our website below. https://www.thorlabs.com/images/TabImages/DiffuserAngularTransmission_780.gif

Hashimadelbanah (posted 2018-10-15 04:38:15.013)

Hi, I would like to know what is the damage threshold for this diffuser? In other words, what is the maximum power this diffuser can hold out? One last question, what does Grit means? Thanks.

nbayconich (posted 2018-10-23 04:32:28.0)

Thank you for contacting Thorlabs. We have not done official laser damage threshold testing for our UVFS ground glass diffusers, however being that the surfaces are ground and not polished as our windows are, the theoretical damage threshold for UVFS diffusers would be lower than that of a UVFS polished window. The grit number refers to the size of the grit used to polish the surface of the UVFS material, lower grit number meaning a coarser or larger grit particle size. I will reach out to you directly to discuss your application.

nimrod.nisism (posted 2018-09-27 16:51:23.163)

I would like to purchase the the DGUV10-1500 but with larger diameter > 2" can you help me ? BR, Nimrod Nissim

YLohia (posted 2018-09-27 12:30:29.0)

Hello Nimrod, we will reach out to you directly to discuss the feasibility of offering this. Custom items should be requested by contacting techsupport@thorlabs.com.

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UV Fused Silica Ground Glass Diffusers

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