BH-L19 Longpass Filter
Capture cyan to infrared light with clean green and blue rejection for multi-channel microscopy systems.
- Passband: 514 – 780 nm, 91.2 – 96.0 % T (± 2.4 % ripple)
- Cut-on (T50): ≈ 502 nm
- Edge steepness: ~26 nm (10 → 90 % transition)
- Blocking: < 0.93 % T below 467 nm (OD ≥ 2)
- AOI: 0° (normal incidence); custom angles available
- Construction: Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick
- Custom options: Edge tuning, ripple smoothing, 45° AOI, rapid prototypes
Learn more
BH-L19 Hybrid delivers Passband 514 – 780 nm, 91.2 – 96.0 % T (± 2.4 % ripple), Cut-on (T50) ≈ 502 nm, and Edge steepness ~26 nm (10 → 90 % transition).
The hard-oxide coating is built for repeated handling, heat, and cleaning.
Best suited for:
Blue-glare suppression in machine vision and surveillance, GFP and FITC fluorescence collection, daylight sensor protection, cyan LED filtering, and blue-scatter rejection in scientific microscopy.
Description
The BH-L19 is the shortest-cut-on longpass in the series, with its 50 % transition at 502 nm. It passes from 510 nm through the full visible and NIR spectrum with average transmission above 94 %, peaking at an impressive 96 % near 567 nm - the highest peak of any longpass filter in this lineup. Blocking holds below 1 % from 380 to 482 nm, rejecting UV, violet, and blue with OD 2+ suppression. This broad-pass filter covers the widest spectral window in the series.
Key Advantages
- 502 nm cut-on for maximum coverage - T50 % at 502 nm passes the widest possible longpass window - cyan through NIR in a single filter.
- 96 % peak transmission - Highest peak in the longpass series at 567 nm, demonstrating exceptionally low insertion loss.
- > 94 % average across 270 nm - Flat passband from 510 to 780 nm covering green, yellow, orange, red, and NIR.
- Hard-oxide durability - Ion-assisted sputtered coating resists environmental degradation, heat, and repeated cleaning.
- Custom formats - Round, square, or free-form blanks from 5 mm to 450 mm, thickness 0.21-3.8 mm, on Borofloat, soda-lime, Schott D263 T, or Corning Eagle XG substrates.
Typical Applications
- 488 nm laser emission blocking - Blocks 488 nm argon-ion or diode laser excitation while passing all emission wavelengths above 500 nm.
- Broadband emission collection - Captures fluorescence from GFP, YFP, RFP, and NIR dyes simultaneously in multi-label experiments.
- Color imaging with UV rejection - Removes UV and violet from imaging paths to prevent chromatic aberration and sensor artifacts.
- Environmental & agricultural sensing - Passes the full green-red-NIR window for vegetation indices, water quality, and land-use classification.
- Projection & display testing - Defines a broad warm-plus-green detection window for display characterization systems.
From rapid prototypes to production volumes, KUPO Optics delivers the BH-L19 to your exact specifications - get in touch.
FAQ
BH-L19 FAQ
What is BH-L19 and what is it used for?
BH-L19 is a 500 nm Longpass Filter. The BH-L19 is the shortest-cut-on longpass in the series, with its 50 % transition at 502 nm. It passes from 510 nm through the full visible and NIR spectrum with average transmission above 94 %, peaking at an impressive 96 % near 567 nm - the highest peak of any longpass filter in this lineup. Common uses include 488 nm laser emission blocking, Broadband emission collection, Color imaging with UV rejection, and Environmental & agricultural sensing.
What are the key optical specs of BH-L19?
Key published specs for BH-L19 include Passband: 514 – 780 nm, 91.2 – 96.0 % T (± 2.4 % ripple); Cut-on (T50): ≈ 502 nm; Edge steepness: ~26 nm (10 → 90 % transition); Blocking: < 0.93 % T below 467 nm (OD ≥ 2); AOI: 0° (normal incidence); custom angles available.
What applications is BH-L19 best suited for?
BH-L19 is commonly used for 488 nm laser emission blocking, Broadband emission collection, Color imaging with UV rejection, and Environmental & agricultural sensing. 488 nm laser emission blocking - Blocks 488 nm argon-ion or diode laser excitation while passing all emission wavelengths above 500 nm.
Can BH-L19 be customized for size, substrate, or coating requirements?
KUPO lists the construction for BH-L19 as Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick. Published custom options include Edge tuning, ripple smoothing, 45° AOI, rapid prototypes. Custom formats - Round, square, or free-form blanks from 5 mm to 450 mm, thickness 0.21-3.8 mm, on Borofloat, soda-lime, Schott D263 T, or Corning Eagle XG substrates.
What should I know about angle of incidence and durability for BH-L19?
The published angle of incidence for BH-L19 is 0° (normal incidence); custom angles available. The hard-oxide coating is built for repeated handling, heat, and cleaning.
