BH-A04 UV-Cut Filter
UV-cut window: > 95 % T from 420 – 780 nm, < 0.3 % T below 390 nm—blocks harmful UV while leaving visible colour and brightness untouched.
- Cut-off edge: 50 % T ≈ 415 nm (steep slope)
- UV block: < 0.3 % T from 300 – 390 nm
- Visible pass: 95 ± 2 % T across 420 – 780 nm
- Surface: IBS hard-oxide > 10 H, solvent-safe
- Wavefront: ≤ 0.25 λ P-V @ 632 nm (optional tighter spec)
- Formats: 5 – 450 mm, 0.5 – 3 mm, Borofloat® / silica / soda-lime
Learn more
BH-A04 is KUPO’s broadband UV-cut filter that funnels the entire visible spectrum
through with virtually zero colour cast while shutting down near-ultraviolet energy. Transmission
leaps past 95 % just above 420 nm and stays flat (±2 %) right out to 780 nm, yet drops below
0.3 % from 300 – 390 nm—protecting CMOS/CCD sensors, optics, and human eyes from damaging UV
without dimming the beam.
Ion-beam-sputtered oxide layers give > 10 H pencil hardness, no yellowing, and humidity
immunity. KUPO supplies round, square, or complex shapes on Borofloat®, fused silica, or
soda-lime glass in thicknesses of 0.5 – 3 mm and sizes up to 450 mm, with prototypes shipping
in about two weeks.
Typical uses: colour-neutral camera windows, machine-vision housings exposed to UV
LEDs, heat shields for high-power stage lights, UV-safe microscope illumination, and AR/VR
cover plates requiring optical-grade cosmetics.
Description
BH-A04 is a UV-cut filter that screens out near-ultraviolet energy while letting the entire visible spectrum sail through almost untouched. Transmission leaps past 90 % just above 417 nm, quickly levels about 90 %, and stays there with only ±2 % ripple all the way to 780 nm. Below 390 nm the coating sends virtually every photon back, keeping sensors, optics, and eyes safe from stray UV without adding colour cast or flare.
Key advantages
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Steep 415 nm edge – < 0.3 % T from 300 – 390 nm protects detectors and glass from UV-induced haze or damage.
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> 95 % broadband pass – flat, neutral transmission through the entire visible range preserves colour fidelity and brightness.
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IBS-hardened stack – dense oxide layers deliver MIL-spec abrasion resistance, no yellowing, and humidity stability.
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Made-to-order formats – round, square, or free-form parts up to 450 mm, 0.5 – 3 mm thick on Borofloat®, fused silica, or soda-lime.
Typical applications
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Digital imaging & cinematography – replace plastic UV filters with a colour-neutral, scratch-tough window.
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Machine-vision enclosures – stop UV LEDs or welding arcs from fogging CMOS sensors while maximising visible signal.
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Architectural & stage lighting – fit in front of high-power fixtures to tame UV without dimming the beam.
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Scientific instrumentation – protect spectrometers or analytical cameras where UV could skew readings or cloud optics.
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Head-mounted & AR displays – act as a clear, invisible cover that blocks UV heat and meets stringent cosmetic specs.
Need prototype pieces next week or high-volume lots next quarter? BH-A04 UV-cut windows can be coated, diced, and shipped to your exact specification—fast.
