CM-845 Cold Mirror & Longpass Filter
CM-845 is a cold mirror, near-IR longpass: transmission stays near baseline through ~300–780 nm (≤1 % T with a narrow 380–390 nm UV spike), then rises across ~810–860 nm to a high IR passband of ~96–99 % T that remains flat past ~1.6 µm—reflecting VIS, passing IR.
- Function: VIS-reflecting / NIR-transmitting longpass (cold mirror)
- VIS leakage: ≤1 % T to ~780 nm; narrow UV spike ~380–390 nm
- Edge position: Rapid 10→90 % rise across ~810–860 nm (~845 nm class)
- IR throughput: ~96–99 % T from ~870–1600 nm; low-ripple, flat passband
- Spectral quality: Stable, smooth IR region for predictable power & calibration
- Substrates & format: Hard dielectric; Borofloat®, Eagle XG, D263 T, or soda-lime • 5–450 mm • 0.21–3.8 mm • options: rear-AR & slight wedge
Learn more
CM-845 reflects bright visible back into the beam while venting IR to dumps or sensors—cooler optics with higher luminous efficiency. The steep long-wave edge cleanly separates paths, and the flat IR passband simplifies detector calibration and thermal design.
Typical applications • Illumination optics & light engines (reflect VIS, vent IR heat) • Projectors & cinema lamps (protect phosphor wheels/LCD/LCOS) • Microscopy & biomedical lighting (cooler epi-illumination, head-lamps) • Machine-vision illuminators (deliver IR to sensors) • Architectural & entertainment lighting (manage temperature without sacrificing visible output).
Need test chips tomorrow or thousands next quarter? CM-845 longpass filters are coated and cut-to-size (including dicing) to your exact spec—fast.
Description
CM-845 is a cold mirror, near-IR longpass. It reflects the visible band and passes infrared: transmission stays near the baseline through ~300–780 nm (generally ≤1% T with a narrow UV spike around ~380–390 nm), then rises across ~810–860 nm to a high IR passband of ~96–99% T that remains flat out past ~1.6 µm.
Key advantages
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High IR throughput — ~96–99% T from ~870–1600 nm supports efficient thermal management and IR sensing.
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Steep ~845 nm edge — rapid 10-to-90% rise across ~810–860 nm cleanly separates reflected VIS from transmitted IR.
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Low VIS leakage — near-baseline %T through the visible for effective cold-mirror operation (note the small UV spike).
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Stable, low-ripple passband — smooth IR region simplifies power delivery and detector calibration.
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Durable dielectric stack — abrasion and humidity resistant for field, stage, and lab use.
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Flexible glass choices — Borofloat®, Eagle XG, or D263 T (0.21–3.8 mm) for high-temp duty to ~450 °C; soda-lime for ≤150 °C. Custom sizes 5–450 mm; rear-surface AR and slight wedge available to suppress ghosts.
Typical applications
-
Illumination optics & light engines — reflect bright VIS into the beam while venting IR heat.
-
Projectors & cinema lamps — protect phosphor wheels and LCD/LCOS engines from thermal load.
-
Microscopy & biomedical lighting — cooler epi-illumination and head-lamps.
-
Machine-vision illuminators — deliver IR to sensors while keeping VIS out of the path.
-
Architectural & entertainment lighting — manage fixture temperature without sacrificing visible output.
Need test chips tomorrow or thousands next quarter? CM-845 longpass filters are coated and cut-to-size (including dicing) to your exact spec—fast.
