BH-A07 Cold Mirror Filter
Cold-mirror IR-pass: > 92 % T from 750 – 1100 nm and < 1 % T in the entire 375 – 650 nm band—channels heat-carrying IR while bouncing visible light away.
- IR passband: ≥ 92 % T @ 750 – 1100 nm (peak efficiency)
- Visible block: < 1 % T 375 – 650 nm (99 % reflection)
- Cut-on edge: 50 % T ≈ 730 nm, steep < 40 nm slope
- Architecture: Cold-mirror; reflects visible heat instead of absorbing it
- Thermal relief: 50–80 % lower substrate ΔT under high-flux lamps
- Durability: IBS stack meets MIL-M-13508C abrasion / adhesion / humidity
- Formats: ≤ 350 × 350 mm, 0.7 – 6 mm on Borofloat®, D 263 T, fused silica, sapphire
Learn more
BH-A07 is KUPO’s cold-mirror IR-pass filter that reflects almost the entire
visible spectrum while sending near-infrared energy straight through. That means you
can dump luminous heat before it reaches colour wheels, light pipes, lenses, or
sensors—cutting substrate temperatures by up to 80 % compared with absorption-based
glass.
The ion-beam-sputtered oxide design drives transmission above 92 % from roughly
750 nm to 1.1 µm and holds it near 90 % out to 1.2 µm, while visible light from
375 – 650 nm is reflected at > 99 %. The stack exceeds MIL-M-13508C requirements for
abrasion, adhesion, humidity, and salt-fog, so it’s ready for harsh production lines,
outdoor enclosures, and touring stage rigs.
We supply rounds or squares up to 350 × 350 mm in 0.7 – 6 mm thickness on
Borofloat®, Schott D 263 T, fused silica, or sapphire. Custom edge shifts, angle-of-incidence
tuning, and dual-side AR options are available, with prototype lots shipping in as
little as ten days.
Typical uses: projector integrator heat dumps, covert NIR illuminators, IR/visible
beam splitters in fluorescence and phototherapy systems, 808/850/940 nm lidar or
ToF optics, and IR-tracking paths in architectural or entertainment lighting.
Description
BH-A07 is a cold-mirror IR-pass filter designed to dump visible-light energy while channeling near-IR (> 92 % T) for heat management or dual-band imaging. Transmission rises sharply at ~750 nm and remains above 90 % out to 1.2 µm, while the 375 – 650 nm region is suppressed to < 1 %—meaning almost all visible light is reflected rather than absorbed, keeping downstream components cool and stray-light free.
Key advantages
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High IR throughput – ≥ 92 % T from ~750 – 1100 nm maximises detector signal or fibre coupling efficiency.
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Deep visible rejection – < 1 % T across 375 – 650 nm reflects up to 99 % of unwanted luminous power.
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Thermal relief – reflecting, rather than absorbing, visible heat cuts substrate temperature rise by 50–80 % in high-flux systems.
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Rugged IBS stack – meets MIL-M-13508C abrasion, adhesion, humidity, and salt-fog requirements for field or production use.
Typical applications
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Projector integrators & condenser assemblies – dump visible-band heat before the colour wheel or light pipe.
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Machine-vision illuminators – create covert NIR lighting while shielding cameras from stray visible glare.
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Scientific & medical optics – split IR excitation from visible observation in fluorescence or phototherapy rigs.
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Laser-based 3-D sensing – steer 808-, 850-, or 940-nm beams through while protecting optics from ambient daylight.
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Architectural & entertainment lighting – allow IR effects or cue-tracking while reflecting bright stage light away from sensors.
Standard parts ship in rounds or squares up to 350 mm × 350 mm, 0.7–6 mm thick, on Borofloat®, D 263 T, fused silica, or sapphire. Custom edge shifts, AOI tuning, and dual-side AR options are available on request.
FAQ
BH-A07 FAQ
What is BH-A07 and what is it used for?
BH-A07 is a Cold Mirror. The BH-A07 Cold Mirror is the spectral inverse of a hot mirror, designed to selectively pass near-infrared and short-wave infrared radiation while efficiently rejecting visible light. With peak transmission of 95.6 % at 1198 nm and sustained >80 % transmission from 745-1200 nm, the BH-A07 simultaneously achieves exceptional visible blocking below 5 % across the entire 300-723 nm spectrum. Common uses include Thermal Imaging Systems, Infrared Thermography, Laser Power Monitoring, and Hyperspectral Imaging.
What are the key optical specs of BH-A07?
Key published specs for BH-A07 include Centre wavelength (CWL): 920 nm; Bandwidth (FWHM): 361 nm; Peak transmittance: ≥ 95.5 % T; Short-wave edge (T50): ≈ 739 nm; Long-wave edge (T50): ≈ 1100 nm.
What applications is BH-A07 best suited for?
BH-A07 is commonly used for Thermal Imaging Systems, Infrared Thermography, Laser Power Monitoring, and Hyperspectral Imaging. Thermal Imaging Systems - Passes infrared thermal radiation while rejecting 95 % of visible daylight, enabling daytime thermal imaging and surveillance without solar washout.
Can BH-A07 be customized for size, substrate, or coating requirements?
KUPO lists the construction for BH-A07 as Ion-assisted hard-oxide; 5 – 450 mm shapes, 0.21 – 3.8 mm thick. Published custom options include CWL tuning, bandwidth adjustment, custom blocking range, rapid prototypes. Custom Format Flexibility - Round, square, and free-form geometries from 5-450 mm with Borofloat, soda-lime, Schott D263 T, and Corning Eagle XG substrate options.
What should I know about angle of incidence and durability for BH-A07?
The published angle of incidence for BH-A07 is 0° (normal incidence); custom angles available. The hard-oxide coating is built for repeated handling, heat, and cleaning.
