AR-Coated, N-BK7 Ground Glass Diffusers
- AR-Coated for 350 - 700 nm or 650 - 1050 nm
- Unmounted Diffusers Offered in 120, 220, 600, and 1500 Grit Polishes
- Polished for Greater Uniformity than Sand Blasting
AR-Coated Transfusers Provide Enhanced Transmission Compared to Their Uncoated Counterparts
|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|
- Ø1", Unmounted Circular Diffusers
- One of Two AR Coatings on Both Surfaces:
- 350 - 700 nm (A Coating)
- 650 - 1050 nm (B Coating)
- Substrate Material: N-BK7
Thorlabs' AR-Coated 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 with an AR coating deposited on both sides for either 350 - 700 nm or 650 - 1050 nm. These diffusers offer improved transmission over their uncoated counterparts (see the Graphs Tab for more details).
Polished diffusers are advantageous over sand blasted diffusers, as their surface 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. When mounting the diffusers, the grit polished side should face away from the source.
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.
|Diameter||1.00" (25.4 mm)|
|Clear Aperture||>90% of Diameter|
|Surface Flatness of Smooth Side (@ 633 nm)||<4λ|
|Surface Quality of Smooth Side||80-50 Scratch-Dig|
|Item #||Grit||AR Coating Range|
|DG10-120-A||120||350 - 700 nm
Ravg<0.5%, 0° AOI (Polished Side)a
|DG10-120-B||120||650 - 1050 nm
Ravg<0.5%, 0° AOI (Polished Side)a
The coated diffusers offer increased transmission over their uncoated counterparts, which are represented by the blue curves in the graphs below. The blue-shaded region represents the wavelength range over which the AR coating is specified. The -A coating is specified for 350 - 700 nm and the -B coating for 650 - 1050 nm. 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
These graphs describe the diffusers' behavior before the AR coating has been applied. 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.