HM-650 Hot Mirror & UV-IR Cut Filter
Reject near-infrared heat starting at mid-spectrum while preserving full visible sensitivity and exceptional transparency.
- Passband (visible): 408–636 nm, 85.4–98.9 % T
- Cut-off (T50): ≈ 646 nm
- Edge steepness: ~30 nm (90 → 10 % transition)
- IR rejection: < 0.5 % T from 701–1124 nm (OD ≥ 1.3)
- 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, extended IR blocking range, 45° AOI for beam-steering, rapid prototypes
Learn more
HM-650 Hybrid delivers Passband (visible) 408–636 nm, 85.4–98.9 % T, Cut-off (T50) ≈ 646 nm, and Edge steepness ~30 nm (90 → 10 % transition).
The hard-oxide coating is built for repeated handling, heat, and cleaning.
Best suited for:
Blue-red imaging systems, thermal laser protection, RGB camera pre-filtering, biosensor and fluorescence microscopy, medical imaging with visible LED excitation, high-transmission illumination optics.
Description
The HM-650 is the shortest-cutoff hot mirror in the standard series, with a 50 % crossover at 646 nm and peak transmission of 98.9 % at 581 nm. It passes blue (94.2 %), green (97.7 %), and yellow (98.6 %) with exceptional efficiency-among the highest transmission values across the lineup. However, red is heavily suppressed to 47.6 %, making HM-650 a yellow-green specialist. The payoff is decisive infrared rejection: NIR(700-850) drops to 0.2 % and NIR(850-1000) to 0.3 %. This makes HM-650 the most aggressive IR blocker for applications where red light is unwanted and thermal rejection must be absolute.
Key Advantages
- Highest blue-green transmission - Peak efficiency of 98.9 % and blue (94.2 %), green (97.7 %), yellow (98.6 %) all exceed 94 %. Maximum visible brightness in the blue-green spectrum for vivid, bright illumination.
- Deep, clean IR blocking - NIR(700-850) transmission plunges to 0.2 % and above 850 nm to 0.3 %. Aggressive thermal rejection suitable for heat-sensitive optics, high-power systems, and thermal-noise-intolerant sensors.
- Hard-oxide ion-assisted coating - Advanced durable coating endures thermal cycling, mechanical stress, and high-intensity light exposure without delamination, cracking, or transmission loss.
- Red-free environment - The aggressive red suppression (47.6 %) eliminates red-light contamination in applications where red wavelengths would introduce unwanted glint, autofluorescence, or measurement error.
- Complete custom fabrication capability - Round, square, 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
- Blue-green laser systems - Argon and DPSS laser applications that require maximum blue-green transmission while blocking red and thermal noise from competing light sources.
- Medical and dental white-light systems - Passes blue-green illumination for tissue visualization while blocking red and thermal radiation that could harm sensitive soft tissue or cause patient discomfort.
- Machine vision with blue-green filters - Enables high-contrast machine vision by passing blue-green illumination while rejecting red glint and thermal background in high-speed inspection.
- Botanical and environmental imaging - Blue-green light penetrates water and foliage efficiently; the aggressive IR block eliminates thermal noise when imaging submerged or outdoor specimens.
- High-power cooling-critical optics - Absolute IR blocking protects heat-sensitive optics and detectors in high-power applications where red and thermal radiation pose cooling or damage risks.
KUPO Optics delivers HM-650 in rapid prototypes and production volumes with full customization of diameter, shape, thickness, and substrate material.
FAQ
HM-650 FAQ
What is HM-650 and what is it used for?
HM-650 is a Short-Wave Cutoff for Maximum Visible Preservation. The HM-650 is the shortest-cutoff hot mirror in the standard series, with a 50 % crossover at 646 nm and peak transmission of 98.9 % at 581 nm. It passes blue (94.2 %), green (97.7 %), and yellow (98.6 %) with exceptional efficiency-among the highest transmission values across the lineup. Common uses include Blue-green laser systems, Medical and dental white-light systems, Machine vision with blue-green filters, and Botanical and environmental imaging.
What are the key optical specs of HM-650?
Key published specs for HM-650 include Passband (visible): 408–636 nm, 85.4–98.9 % T; Cut-off (T50): ≈ 646 nm; Edge steepness: ~30 nm (90 → 10 % transition); IR rejection: < 0.5 % T from 701–1124 nm (OD ≥ 1.3); AOI: 0° (normal incidence); custom angles available.
What applications is HM-650 best suited for?
HM-650 is commonly used for Blue-green laser systems, Medical and dental white-light systems, Machine vision with blue-green filters, and Botanical and environmental imaging. Blue-green laser systems - Argon and DPSS laser applications that require maximum blue-green transmission while blocking red and thermal noise from competing light sources.
Can HM-650 be customized for size, substrate, or coating requirements?
KUPO lists the construction for HM-650 as Ion-assisted hard-oxide; 5–450 mm shapes, 0.21–3.8 mm thick. Published custom options include Edge tuning, extended IR blocking range, 45° AOI for beam-steering, rapid prototypes. Complete custom fabrication capability - Round, square, 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 HM-650?
The published angle of incidence for HM-650 is 0° (normal incidence); custom angles available. The hard-oxide coating is built for repeated handling, heat, and cleaning.
