R16 Longpass Filter
Long-pass filter blocking green-cyan (< 610 nm) while passing 92 – 94 % rich red light (655 – 780 nm) for warm, glare-free output.
- Red passband: 655 – 780 nm, 92 – 94 % T (± 2–3 % ripple)
- Cut-on (T50): ≈ 640 nm
- Edge steepness: ~30 nm (10 → 90 % transition)
- Blue-green blocking: < 1 % T below 610 nm
(~20–25 % bump @ 395 nm, suppressible) - Construction: Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick
- Custom options: UV-ripple flattening, edge tuning, 45° AOI, rapid prototypes
Learn more
R16 keeps transmission below one percent up to ~610 nm, reaches the
50 % point near 640 nm, and clears 90 % by ~655 nm. It then rides a smooth
92 – 94 % plateau out past 780 nm, with ripple contained to ±2–3 %.
A modest 20–25 % bump around 395 nm can be flattened in custom runs for
strict UV/blue rejection. KUPO coats Borofloat®, soda-lime, Schott D263 T,
or Corning Eagle XG substrates in any outline—from 5 mm chips to 450 mm
plates, 0.21 – 3.8 mm thick—and can ship prototypes in about two weeks.
Typical uses: LED colour tuning, far-red fluorescence capture,
cyan-glare suppression in machine vision, daylight-to-tungsten warming for
film lighting, and AR/HUD red-graphic injection without blue-green bleed.
Description
R16 keeps transmission below 1 % right up to about 610 nm, crosses 50 % near 640 nm, and clears 90 % by roughly 655 nm. It then holds a flat 92–94 % plateau out past 780 nm with ripple confined to ±2–3 %. A modest 20–25 % bump around 395 nm can be suppressed in custom runs. Use R16 anywhere you need clean, high-power red—warming LED fixtures, collecting far-red fluorescence, or stripping green glare from machine-vision cameras.
Key advantages
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Sharp green-cyan cutoff – 50 % cut-on ≈ 640 nm; < 1 % T maintained to ~610 nm to minimise shorter-wavelength leak.
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High, flat red passband – 92–94 % T from ~655 nm to 780 nm keeps brightness and colour balance stable.
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Optional UV peek control – Small ~395 nm ripple can be flattened for applications needing total blue rejection.
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Hard-oxide durability – Ion-assisted coating resists heat, humidity, solvents, and repeated cleaning.
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Format versatility – Round, square, or custom blanks from 5 mm to 450 mm, 0.21–3.8 mm thick, on Borofloat®, soda-lime, Schott D263 T, or Corning Eagle XG glass.
Typical applications
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LED colour tuning – Remove cool spikes in white or RGB fixtures for warm, red-rich ambience.
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Fluorescence emission – Collect far-red probes (Cy5, Alexa 647, mPlum) while blocking green-cyan excitation.
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Machine vision – Strip cyan reflections from shiny parts while keeping the red channel bright for defect detection.
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Photography & cinema lighting – Warm daylight LED panels toward a tungsten look without gels.
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AR / HUD optics – Inject red graphics cleanly, with negligible blue-green bleed toward the viewer.
Need a quick prototype or a high-volume run? R16 filters can be coated, diced, and shipped to your exact specifications—fast.
