CM-770 Cold Mirror & Longpass Filter

The CM-770 extends the visible-blocking boundary into the near-infrared, with a 50 % cut-on point positioned at 770 nm and peak transmission of 96.4 % at 811 nm. Visible extinction is comprehensive (UV 1.7 %, blue 0.1 %, green 0.2 %, red 0.1 %), while the early NIR (700-850 nm) sits at 51.6 % to establish a tunable blocking transition. Beyond 850 nm, transmission surges to 94.7 % (NIR 850-1000 nm) and holds steady at 94.9 % (SWIR 1000-1200 nm). This asymmetric profile makes the CM-770 ideal for applications demanding suppression of visible light and early-NIR scatter while passing only deep infrared wavelengths.

Key Advantages

• Tuned NIR Rejection - Blocks 700-770 nm to eliminate near-infrared noise from ambient sources and LED leakage, critical for clean thermal signatures in crowded optical fields
• High SWIR Pass Efficiency - > 94 % transmission from 850 nm onward enables sensitive long-wavelength IR detection without secondary filtering losses
• Hard-Oxide Ion-Assisted Design - Engineered for high durability under thermal stress, mechanical handling, and environmental contamination without coating delamination
• Diverse Custom Formats - Supplied as round, square, and free-form blanks ranging from 5 mm to 450 mm with thickness 0.21-3.8 mm on Borofloat, soda-lime, Schott D263 T, or Corning Eagle XG substrates
• Optimized for Medium-Volume Scaling - Coating process balances rapid iteration with consistent batch uniformity, supporting both development prototypes and commercial production

Typical Applications

• Selective Thermal Isolation - Separates visible and near-IR components from deep-IR thermal signals, enabling precise thermal mapping in industrial furnaces and kiln monitoring
• Night Vision + IR Fusion - Combines visible-light night-vision channels with filtered thermal IR in hybrid surveillance optics without spectral overlap
• Mid-Infrared Spectroscopy - Blocks short-wavelength scatter and visible-light noise to improve signal-to-noise ratios in absorption and emission measurements
• Laser Safety & Beam Steering - Directs infrared laser beams while rejecting visible alignment guides and ambient scattered light
• Temperature-Gradient Analysis - Isolates temperature-dependent IR signatures in material science and semiconductor thermal profiling by eliminating NIR ambiguity

The CM-770 bridges the gap between standard visible-blocking and deep-IR applications. We can prototype custom apertures within weeks and scale to volume production without performance compromise.