B11812 Shortpass Filter
High-contrast short-pass filter passing > 90 % in the 410 – 525 nm band while crushing visible-to-NIR light beyond 560 nm for pure blue illumination.
- Blue passband: 410 – 525 nm, 92 – 94 % T
- Cutoff (T50): ~550 nm
- Edge steepness: ≈ 10 nm 90 → 10 % transition
- Blocking: < 0.5 % T from 600 – 740 nm
- NIR leak: Slight rise > 750 nm (customisable flat)
- Construction: Ion-assisted hard-oxide dielectric; 5 – 450 mm custom shapes
Learn more
B11812 is KUPO Optics’ go-to short-pass when you need a bright blue band
and near-total rejection of green, red, and infrared light. Transmission
races past 90 % by ~410 nm, stays flat at 92 – 94 % through about 525 nm, then
plunges below 1 % just after 585 nm. From 580 nm to ~740 nm the curve hugs
the baseline, shielding detectors from flare and thermal noise. A modest
rise above 750 nm can provide an alignment glint—or be flattened in
custom builds. Rugged ion-assisted coatings shrug off heat, humidity, and
solvents, and KUPO can shift edges, suppress ripples, supply 45° AOI
versions, or cut large plates in as little as two weeks.
Typical applications: fluorescence microscopy & cytometry,
blue-LED curing and lithography, machine-vision illumination,
spectroscopy & Raman, and AR/VR combiners where vivid blue graphics must
avoid polluting green-red channels.
Description
B11812 is KUPO Optics’ go-to short-pass filter when you need a clean, bright blue band and near-total rejection of everything green, red, and infrared. Transmission races past 90 % by ~410 nm, stays flat at 92 – 94 % through roughly 525 nm, then collapses below 1 % just after 545 nm. From 580 nm out to about 740 nm the curve hugs the baseline, keeping sensors safe from visible flare and thermal noise. A small rise above 750 nm can serve as a built-in alignment glint—or be flattened in custom builds.
Key advantages
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Brilliant blue window – > 90 % T across 410 – 525 nm for LED, laser, or fluorescence excitation.
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Ultra-steep 540 nm edge – ≈ 10 nm transition cleanly separates blue from green, minimising colour bleed.
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Deep out-of-band blocking – < 0.5 % T from 600 – 740 nm shields detectors and optics from stray light and heat.
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Hard-oxide durability – Ion-assisted layers shrug off heat, humidity, solvents, and frequent wipe-downs.
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Rapid custom options – Edge shifts, ripple suppression, 45 ° AOI designs, or large formats in as little as two weeks.
Typical applications
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Fluorescence microscopy & cytometry – Excite CFP/FITC lines while dumping visible emission bands.
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Blue-LED curing & lithography – Pass 405 – 450 nm light for photoresists while blocking red/IR heat.
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Machine-vision illumination – Pair with 450 nm LED bars to heighten contrast on plastics, textiles, or security inks.
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Spectroscopy & Raman – Isolate blue pump beams for stable baselines and higher SNR.
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AR/VR combiners – Inject vivid blue graphics without polluting green-red channels; optional NIR glint aids eye-tracking.
Need tiny chips, odd shapes, or high-volume OEM supply? KUPO Optics can prototype and ship B11812 from 10 mm slivers up to 300 mm plates—fast.
