R2613 Longpass Filter
Collect pure red and infrared light with steep transition from visible-spectrum blocking.
- Passband: 624 – 780 nm, 90.3 – 95.4 % T (± 2.6 % ripple)
- Cut-on (T50): ≈ 614 nm
- Edge steepness: ~19 nm (10 → 90 % transition)
- Blocking: < 0.95 % T below 593 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
R2613 Hybrid delivers Passband 624 – 780 nm, 90.3 – 95.4 % T (± 2.6 % ripple), Cut-on (T50) ≈ 614 nm, and Edge steepness ~19 nm (10 → 90 % transition).
The hard-oxide coating is built for repeated handling, heat, and cleaning.
Best suited for:
Cy5 and mCherry fluorescence detection, deep color separation in confocal microscopy, red LED and laser filtering, infrared camera preparation, and red-channel imaging in high-resolution systems.
Description
The R2613 transmits the red and near-infrared spectrum from 620 nm onward with its 50 % cut-on at 614.4 nm. The passband averages above 94 % from 620 to 780 nm, peaking at 95.4 % near 713 nm. Blocking is exceptionally deep, averaging just 0.2 % from 380 to 602 nm - one of the lowest blocking floors in the longpass series. This filter provides a pure red-NIR window with virtually zero contamination from shorter wavelengths.
Key Advantages
- 614 nm cut-on for deep-red pass - T50 % at 614.4 nm isolates only red and NIR, blocking the entire visible spectrum from UV through orange.
- OD 2.7+ blocking floor - Average transmission just 0.2 % from 380 to 602 nm is among the deepest in the KUPO longpass lineup.
- 95.4 % peak with flat passband - Uniform throughput above 94 % across 160 nm of red-to-NIR bandwidth.
- Hard-oxide durability - Ion-assisted sputtered coating resists environmental degradation 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
- Deep-red fluorescence imaging - Collects Cy5, Alexa Fluor 647, and far-red protein emission while blocking all common excitation wavelengths.
- H-alpha astronomical imaging - Passes the H-alpha emission line at 656.3 nm and the surrounding red-NIR continuum for nebula and solar imaging.
- NIR sensing & surveillance - Defines a red-NIR detection window for covert illumination, LIDAR, and range-finding systems.
- Blood & tissue analysis - Passes the hemoglobin and deoxy-hemoglobin absorption bands for spectroscopic tissue characterization.
- Laser safety filtering - Blocks green and blue laser wavelengths while passing red alignment beams and NIR process wavelengths.
KUPO Optics delivers the R2613 to your exact specifications - from rapid prototypes to production volumes. Contact us.
FAQ
R2613 FAQ
What is R2613 and what is it used for?
R2613 is a 615 nm Longpass Filter. The R2613 transmits the red and near-infrared spectrum from 620 nm onward with its 50 % cut-on at 614.4 nm. The passband averages above 94 % from 620 to 780 nm, peaking at 95.4 % near 713 nm. Common uses include Deep-red fluorescence imaging, H-alpha astronomical imaging, NIR sensing & surveillance, and Blood & tissue analysis.
What are the key optical specs of R2613?
Key published specs for R2613 include Passband: 624 – 780 nm, 90.3 – 95.4 % T (± 2.6 % ripple); Cut-on (T50): ≈ 614 nm; Edge steepness: ~19 nm (10 → 90 % transition); Blocking: < 0.95 % T below 593 nm (OD ≥ 2); AOI: 0° (normal incidence); custom angles available.
What applications is R2613 best suited for?
R2613 is commonly used for Deep-red fluorescence imaging, H-alpha astronomical imaging, NIR sensing & surveillance, and Blood & tissue analysis. Deep-red fluorescence imaging - Collects Cy5, Alexa Fluor 647, and far-red protein emission while blocking all common excitation wavelengths.
Can R2613 be customized for size, substrate, or coating requirements?
KUPO lists the construction for R2613 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 R2613?
The published angle of incidence for R2613 is 0° (normal incidence); custom angles available. The hard-oxide coating is built for repeated handling, heat, and cleaning.
