BBP-470A Bandpass Filter
BBP-470A isolates the blue channel with ~90 % throughput across ~455–500 nm and near-baseline leakage across the rest of VIS–NIR—built for excitation and high-contrast imaging.
- Main passband (T): ~88–91 % T @ 455 – 500 nm
- Cut-on / cut-off: Steep edges around ~450 nm and ~505 nm
- Out-of-band (VIS–NIR): ~0–2 % T across ~300 – 1100 nm
- SWIR window: ~85–88 % T @ 1180 – 1210 nm (optional extra blocking)
- Ghost control: Optional rear AR and slight wedge available
- Substrates: Borofloat®, Eagle XG, D263 T (≤ 450 °C), soda-lime (≤ 150 °C)
- Size / thickness: 5 – 450 mm • 0.21 – 3.8 mm (custom cut & dicing)
Learn more
BBP-470A is a visible bandpass centred near 470 nm, delivering a high-transmission
blue window (~88–91 %) across ~455–500 nm with steep edges for clean colour separation. Outside the
main passband, transmission stays near baseline (~0–2 %) across most of the 300–1100 nm range,
keeping mixed illumination from washing out contrast or overloading sensors.
One important note: the spectrum shows a strong secondary window in the far red / short-wave infrared
near ~1180–1210 nm (peaking ~85–88 %). If your detector has response there, KUPO can add an
additional blocking stack to fully suppress that band.
Typical uses: blue excitation for fluorescence, 470 nm LED inspection lighting, microscopy
colour-channel isolation, projection/instrument channel selection, and photometry where stable blue
throughput matters. KUPO supplies rear-surface AR, slight wedge, and rapid custom cutting—from small
test chips to 450 mm plates—on high-temp glass (Borofloat®, Eagle XG, D263 T) or economical soda-lime.
Description
BBP-470A is a visible bandpass filter centred in the blue (~470 nm). It delivers a high transmission window of about ~88–91% around ~455–500 nm, with steep edges that quickly suppress adjacent wavelengths. Outside the main passband, transmission stays near the baseline (generally ~0–2% across most of ~300–1100 nm), with small residual ripples. The spectrum also shows a pronounced secondary transmission window in the far red/SWIR near ~1180–1210 nm (peaking around ~85–88% T), which is worth noting if your detector is sensitive out there.
Key advantages
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High blue throughput: ~88–91% T through the main ~470 nm band for efficient blue LED and excitation use.
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Steep band edges: Rapid cut-on/cut-off for clean separation from nearby wavelengths.
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Low out-of-band leakage (VIS–NIR): Near-baseline transmission across most of ~300–1100 nm reduces background and improves contrast.
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SWIR leakage awareness: A strong secondary window appears near ~1180–1210 nm; additional blocking can be added if required.
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Production-ready build: Durable dielectric coating; optional rear-surface AR and slight wedge available to suppress ghosts/flare.
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Custom formats: Borofloat®, Eagle XG or D263 T (0.21–3.8 mm) for high-temp use to ~450 °C; economical soda-lime for ≤150 °C. Custom sizes 5–450 mm.
Typical applications
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Blue excitation (fluorescence/biotech): Isolate blue excitation while suppressing background for higher signal-to-noise.
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470 nm LED illumination: Improve contrast in machine vision and inspection systems.
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Microscopy & imaging: Band-limited blue channel for cleaner colour separation.
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Projection & optical instruments: Spectral channel selection and stray-light control.
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Photometry & sensing: Stable blue band for reflectance or absorption measurements.
Need test chips tomorrow or thousands next quarter? BBP-470A filters are coated and cut-to-size (including dicing) to your exact spec—fast.
