CM-618 Cold Mirror & Longpass Filter
CM-618 is a cold mirror, deep-red/IR longpass: transmission stays near baseline through ~300–600 nm (≤1–2 % T with small resonant bumps), then rises steeply across ~610–630 nm to ~96–100 % T from ~630–980 nm. Beyond 1.0 µm it shows a shallow trough ~1.05–1.12 µm (~88–92 % T) and recovers to ~92–95 % T by ~1.2 µm.
- Function: VIS-reflecting / deep-red+IR-transmitting longpass (cold mirror)
- Edge position: Steep 10→90 % rise across ~610–630 nm (~20–30 nm)
- Passband: ~96–100 % T ~630–980 nm; shallow trough ~1.05–1.12 µm (~88–92 % T); ~92–95 % T by ~1.2 µm
- VIS leakage: ≤1–2 % T to ~600 nm; small resonant bumps; strong UV suppression <~380 nm
- Durability: Low-scatter hard dielectric; abrasion & humidity resistant
- Substrates & format: Borofloat®, Eagle XG, D263 T, or soda-lime; 5–450 mm • 0.21–3.8 mm; rear-AR & slight wedge options (to ~450 °C; ≤150 °C for soda-lime)
Learn more
CM-618 reflects blue/green back into the beam while venting deep-red/NIR to dumps or sensors—cooler optics with high luminous efficiency. The sharp ~618 nm edge cleanly splits paths, and the smooth IR passband enables predictable power delivery.
Typical applications • Illumination optics & light engines (reflect blue/green, vent deep-red/NIR heat) • Laser/diode management (transmit 633/650 nm, reflect shorter) • Machine-vision illuminators (deliver NIR to sensors, minimal VIS leakage) • Microscopy & biomedical lighting (cooler epi-illumination, head-lamps) • Architectural & entertainment lighting (manage temperature, maintain colour output).
Need test chips tomorrow or thousands next quarter? CM-618 longpass filters are coated and cut-to-size (including dicing) to your exact spec—fast.
Description
CM-618 is a cold mirror, deep-red/IR longpass. It reflects blue–green content and passes red plus infrared: transmission stays near the baseline through ~300–600 nm (generally ≤1–2% T with small resonant bumps), then rises steeply across ~610–630 nm to a high passband of ~96–100% T from ~630–980 nm. Beyond ~1.0 µm the curve shows a shallow trough around ~1.05–1.12 µm (~88–92% T) and recovers to ~92–95% T by ~1.2 µm.
Key advantages
-
High deep-red/IR throughput — ~96–100% T from ~630–980 nm, remaining >~90% to ~1.2 µm.
-
Steep ~618 nm edge — rapid 10-to-90% rise (~20–30 nm) cleanly separates reflected blue/green from transmitted red/IR.
-
Low VIS leakage — near-baseline %T through the blue/green band for efficient cold-mirror operation.
-
UV moderation — strong short-wave suppression (<~380 nm) helps reduce fluorescence and sensor haze.
-
Durable dielectric stack — abrasion and humidity resistant for field, stage, and lab use.
-
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 blue/green into the beam while venting deep-red/NIR heat.
-
Laser/diode management — transmit 633/650 nm sources while reflecting shorter wavelengths.
-
Machine-vision illuminators — deliver NIR to sensors with minimal visible leakage.
-
Microscopy & biomedical lighting — cooler epi-illumination and head-lamps.
-
Architectural & entertainment lighting — manage fixture temperature while maintaining colour output.
Need test chips tomorrow or thousands next quarter? CM-618 longpass filters are coated and cut-to-size (including dicing) to your exact spec—fast.
