Schott UG filter glass

Schott UG UV Bandpass Filters, Cut to Size in Rye

Kingsview Optical makes custom UV bandpass filters from Schott UG1, UG11, UG2A and UG5 glass. We CNC shape them to your drawing, polish them on our own lines and coat them in our own chambers, and we can block the red leak with KG glass or a sputtered coating, so you get one finished filter from one UK supplier.

  • Cut and polished in Rye
  • UG1, UG11, UG2A and UG5
  • Coated in-house
  • ISO 9001:2015
Send Your Filter Drawing See the Specification
Schott UG1 UV bandpass filter glass at Kingsview Optical
Schott UG1 filter glass, ready for cutting in Rye.
Filters made here, start to finish. CNC shaped, polished, coated and measured at our site in Rye.
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The basics

What a UV Bandpass Filter Does

In short: a UV bandpass filter passes ultraviolet light and blocks visible light. Schott UG glasses look black because they absorb almost all visible light, while letting a band of UV through.

UG glasses are coloured right through, so they work at any angle of incidence and don't rely on a coating. UG1 is the most widely used, passing a band centred in the UVA. UG11 is similar but with less transmission at the red end. UG5 passes a wider band that reaches further into the deep UV, and also passes more visible red.

All UG glasses let some near-infrared through, typically around 700 to 800nm: the so-called red leak. A silicon detector or camera will see it, so many systems pair the UG filter with a KG heat absorbing filter or a sputtered IR-blocking coating to remove it.

We cut UG filters to any outline on our CNC machines, polish them flat and parallel, and can add UV-optimised AR coatings to lift transmission in the passband.

SourceUVvisiblenear IRUG glassUV passesvisible blockedsome red leak
UG glass passes UV and blocks visible light, with a small red leak.
Transmittance of Schott UG1, UG11, UG2A and UG5 UV bandpass filter glass at 2mm thick
Transmittance of Schott UG1, UG11, UG2A and UG5 at 2mm thick, plotted from Schott data. Note the red leak above 700nm.
Choosing a grade

Which UG Glass Do You Need?

The grades differ in where their UV band sits and how much red and near-infrared leaks through. The chart above is for 2mm thickness. Tell us your source, detector and the wavelengths you need, and we'll suggest a grade and thickness.

GlassWhat it doesTypical use
UG1Passes a UV band centred in the UVA and blocks visible light. Has a red leak above 700nm.UV fluorescence, banknote and document checking, UV LED filtering
UG11Similar UV band to UG1, extending to shorter wavelengths, with less red leak.Where a cleaner UV band is needed, or the detector sees red
UG2AA UV-pass glass with higher transmission in the near-infrared.Applications where infrared transmission is acceptable
UG5A wider band reaching further into the deep UV, with more visible red transmission.Deep UV work, UV lamps and broadband UV sources
The red leakUG glasses transmit some light around 700 to 800nm. Silicon sensors are sensitive there, so the leak can swamp a weak UV signal.
How we block itPair the UG filter with KG heat absorbing glass, cemented or stacked, or add a sputtered IR-blocking coating made in our own chambers.
Applications

Where Our UG Filters Are Used

Fraud detectionChecking banknotes, passports and documents under UV light.
UV fluorescencePassing UV excitation light and blocking visible light from the source.
UV LEDs and lampsCleaning up the visible output of UV sources.
Forensics and inspectionRevealing marks, residues and defects that fluoresce under UV.
Curing and process controlMonitoring UV curing and UV-based processes.
Scientific instrumentsUV transmission filters for spectroscopy and research optics.
Specification

UG UV Bandpass Filter Specification

These are our standard tolerances. If your design needs tighter, tell us which parameter. We'll tell you plainly whether we can hold it, and what it adds to cost.

Size range0.8mm to 100mm
Dimension tolerance±0.1mm
Thickness tolerance±0.05mm
Parallelism (twin lap)Better than 10 arcsec
Surface quality (scratch-dig)60/40 standard, 40/20 on request
GlassSchott UG1, UG11, UG2A and UG5; Hoya equivalents on request
ShapesRound, rectangular and custom outlines, CNC shaped from your drawing or STEP file
CoatingsUV-optimised AR, wide-angle AR, sputtered IR-blocking coatings
Red leak blockingKG glass added to the stack, or a sputtered coating

Not sure what to specify? Tell us the UV wavelength you need to pass, your light source and the detector. Grade, thickness and red leak blocking follow from those.

Options

Made to Fit Your System

CoatingsUV-optimised AR to lift passband transmission, applied in our own chambers
Shapes and edgesRound, rectangular and custom outlines and chamfers, CNC shaped in-house
Sputtered filtersAdd a sputtered IR-blocking coating to remove the red leak Mounts and assembliesFilters fitted into mounts and housings from our own machine shop
Questions

UV Bandpass Filter Questions

What is the difference between UG1, UG11 and UG5?
UG1 passes a band centred in the UVA and is the most widely used. UG11 has a similar band reaching slightly shorter wavelengths, with less red leak. UG5 passes a wider band reaching further into the deep UV, and lets more visible red through.
What is the red leak on UG filters?
UG glasses transmit some near-infrared light, typically around 700 to 800nm. Silicon cameras and photodiodes are sensitive there, so the leak can add unwanted signal. It is blocked by adding KG heat absorbing glass or a sputtered IR-blocking coating.
Can you combine a UG filter with a KG filter?
Yes. We can cut both to the same outline and supply them as a matched pair or stacked assembly, so the KG glass removes the red leak from the UG filter.
Which UG filter should I use for UV fluorescence?
UG1 is the usual choice for UVA excitation, for example with 365nm sources. If your detector picks up the red leak, choose UG11 or add KG glass. Tell us the source and detector and we'll suggest the best combination.
Can you AR coat UG filters for the UV?
Yes. We design and apply UV-optimised AR coatings in our own chambers to lift transmission in the passband.
What do you need to quote a UG filter?
The outline and size, thickness, glass grade, any coating, whether you need the red leak blocked, and quantities for prototype and production. A drawing helps but isn't essential.

Related Filters and Optics

Custom optical filtersSputtered bandpass, notch, longpass, shortpass and dichroic filters Schott KG heat absorbing filtersVisible-pass, infrared-absorbing glass: KG1, KG2, KG3 and KG5 Optical windowsFlat, parallel windows in optical glass, fused silica and sapphire Optical coatingAR, mirror and sputtered coatings applied in our own chambers

Getting a Quote for UG UV Bandpass Filters

Send us your drawing, or just the size, thickness and glass you need. An engineer from the team that would make your filters, not a sales team, will review it and tell you plainly what's achievable and what will drive cost.

What to send

  • Drawing (PDF or STEP), or the size and outline
  • Glass grade and thickness, or the UV wavelength you need
  • Your light source and detector
  • Coating, and whether the red leak must be blocked
  • Quantities: prototypes and expected production volumes

What happens next

  1. An engineer reviews itWithin one working day, flagging anything that will drive cost or lead time.
  2. We quote the filterFor the prototype, and for production at your volumes.
  3. We cut, polish, coat and deliverAll in Rye, with inspection data if you need it.
Start Your RFQ

Need a Custom UV Bandpass Filter?

Send your drawing, or tell us the size, thickness and glass. We'll tell you plainly how we'd make it, what it will cost and how long it will take.

Send Your Filter Drawing Call 01797 226202
Made in Rye, East Sussex. NDA-friendly. Defence and security work welcome. ISO 9001:2015.