R16 Longpass Filter
Deliver deep red and near-infrared collection with outstanding blocking margin below 621 nm.
- Passband: 652 – 780 nm, 91.6 – 95.7 % T (± 2.1 % ripple)
- Cut-on (T50): ≈ 644 nm
- Edge steepness: ~17 nm (10 → 90 % transition)
- Blocking: < 0.87 % T below 621 nm (OD ≥ 2.1)
- 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
R16 Hybrid delivers Passband 652 – 780 nm, 91.6 – 95.7 % T (± 2.1 % ripple), Cut-on (T50) ≈ 644 nm, and Edge steepness ~17 nm (10 → 90 % transition).
The hard-oxide coating is built for repeated handling, heat, and cleaning.
Best suited for:
Alexa 647, Cy5, and deep red fluorescence microscopy, far-red LED and laser systems, NIR imaging and thermal pre-filtering, red-channel separation in hyperspectral imaging, and sensitive photometry applications.
Description
The R16 transmits the deep red and near-infrared spectrum from 649 nm onward, with its 50 % cut-on at 643.9 nm. Transmission peaks at 95.7 % near 767 nm, averaging above 95 % across the 649-780 nm passband - one of the flattest and brightest responses in the longpass series. Blocking averages 0.2 % from 380 to 631 nm, with a mild UV shoulder around 380-385 nm that stays below 5 %.
Key Advantages
- 644 nm cut-on with 95 % average - T50 % at 643.9 nm delivers one of the highest average passbands in the series at 95 %.
- Deep blocking to 631 nm - Average transmission 0.2 % across the full UV-through-orange spectrum with OD 2.7+ rejection.
- 95.7 % peak near 767 nm - Excellent NIR throughput makes this filter suitable for combined visible-red and NIR detection.
- Hard-oxide durability - Ion-assisted sputtered coating resists thermal cycling, humidity, solvents, and mechanical 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
- Far-red & NIR fluorescence - Collects emission from Cy5.5, Alexa 680, and NIR dyes while blocking all visible excitation wavelengths.
- Red-NIR machine vision - Defines the detection window for systems using 650-780 nm LED illumination in industrial inspection.
- Retinal & ophthalmic imaging - Passes the red-NIR window used in fundus photography and OCT auxiliary imaging while blocking visible light.
- Autonomous vehicle sensing - Filters ambient visible light while passing 650-780 nm channels for LIDAR and sensor fusion systems.
- H-alpha & deep-red astronomy - Isolates H-alpha and the deep-red continuum for narrowband nebula imaging and stellar photometry.
Need the R16 in a custom dimension? KUPO Optics delivers prototypes in days and production volumes on your timeline.
FAQ
R16 FAQ
What is R16 and what is it used for?
R16 is a 645 nm Longpass Filter. The R16 transmits the deep red and near-infrared spectrum from 649 nm onward, with its 50 % cut-on at 643.9 nm. Transmission peaks at 95.7 % near 767 nm, averaging above 95 % across the 649-780 nm passband - one of the flattest and brightest responses in the longpass series. Common uses include Far-red & NIR fluorescence, Red-NIR machine vision, Retinal & ophthalmic imaging, and Autonomous vehicle sensing.
What are the key optical specs of R16?
Key published specs for R16 include Passband: 652 – 780 nm, 91.6 – 95.7 % T (± 2.1 % ripple); Cut-on (T50): ≈ 644 nm; Edge steepness: ~17 nm (10 → 90 % transition); Blocking: < 0.87 % T below 621 nm (OD ≥ 2.1); AOI: 0° (normal incidence); custom angles available.
What applications is R16 best suited for?
R16 is commonly used for Far-red & NIR fluorescence, Red-NIR machine vision, Retinal & ophthalmic imaging, and Autonomous vehicle sensing. Far-red & NIR fluorescence - Collects emission from Cy5.5, Alexa 680, and NIR dyes while blocking all visible excitation wavelengths.
Can R16 be customized for size, substrate, or coating requirements?
KUPO lists the construction for R16 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 R16?
The published angle of incidence for R16 is 0° (normal incidence); custom angles available. The hard-oxide coating is built for repeated handling, heat, and cleaning.
