B71305 Shortpass Filter
Ultra-steep short-pass filter passing > 90 % in the 410 – 470 nm band and crashing below 0.5 % past 520 nm for razor-clean UV-blue excitation.
- Peak passband: 410 – 470 nm, 92 – 94 % T
- Cutoff (T50): ~500 nm
- Edge steepness: ≈ 5 nm (90 → 10 % transition)
- Blocking window: < 0.5 % T from 520 – 750 nm
- Construction: Ion-assisted hard-oxide dielectric; 5 – 450 mm custom shapes
Learn more
B71305 is KUPO Optics’ high-contrast short-pass that passes strong UV–blue
light while slamming the door on mid-visible through near-infrared energy.
Transmission climbs past 80 % by 400 nm, peaks around 92 – 94 % through
410 – 470 nm, and then plummets below 1 % by ~500 nm. Beyond 520 nm the
filter holds transmission at detector-noise levels, protecting sensors
from red flare, IR heat, and autofluorescence.
Key advantages include a bright UV-blue window, ultra-steep cutoff,
deep out-of-band blocking (< 0.5 % through 750 nm and < 0.01 % in the
NIR), and hard-oxide durability. Edge tuning, 45 ° AOI versions, or large
plates up to 300 mm are available in as little as two weeks.
Typical applications: fluorescence microscopy & flow cytometry,
UV-LED testing, machine-vision lighting, photolithography & curing, and
blue-excited spectroscopy or Raman setups.
Description
B71305 is KUPO Optics’ high-contrast shortpass that passes strong UV-blue light while slamming the door on mid-visible through near-infrared energy. Transmission climbs quickly past 80 % by 400 nm, peaks around 92 – 94 % through 410 – 470 nm, and then tumbles below 1 % by ~500 nm. From 520 nm to beyond 750 nm the filter holds transmission at essentially detector-noise levels, protecting sensors from red flare, IR heat, and autofluorescence.
Key advantages
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Bright UV-blue window — >90 % T across 410 – 470 nm maximises signal for excitation, inspection, or curing tasks.
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Ultra-steep cutoff — Edge drop of ~5 nm separates desired band from unwanted green/red with minimal color bleed.
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Deep out-of-band blocking — <0.5 % T from 520 – 750 nm shields detectors and prevents ghost images.
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Low stray-light leakage — Integrated <0.01 % T floor in the NIR keeps thermal noise out of sensitive cameras.
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Hard-oxide durability — Ion-assisted layers survive heat, humidity, solvents, and aggressive wipe-downs in production.
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Fast custom shifts — Edge tuning, 45 ° AOI versions, or larger formats ship in as little as two weeks.
Typical applications
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Fluorescence microscopy & flow cytometry — Cleanly excite CFP/FITC families while blocking visible emission bands.
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UV-blue LED testing — Characterise die output without red/NIR contamination.
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Machine-vision lighting — Pair with 450 nm LED bars for high-contrast inspection of pharmaceutical vials, plastics, or security inks.
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Photolithography & curing — Pass reactive 405 nm lines while dumping IR heat that can distort delicate substrates.
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Spectroscopy & Raman — Isolate blue pump beams, improving baseline stability and signal-to-noise ratios.
Need miniature chips for fibre ferrules, trapezoids for waveguides, or volume OEM supply? KUPO Optics can prototype and ship B71305 from 10 mm slivers up to 300 mm plates to keep your project moving.
