Guide
850nm vs 940nm infrared LED bare die
MANULED supplies U.S.-made AlGaAs IR LED bare die at both 850nm and 940nm (and across 850–950nm). This guide summarizes the trade-offs engineers use when picking an illuminator wavelength for cameras, biometrics, and covert lighting.
| Factor | 850 nm | 940 nm |
|---|---|---|
| Visible glow | Faint red glow often visible in dark rooms | Much lower visible glow; more covert operation |
| Typical sensor response | Higher response on many silicon NIR cameras | Slightly lower response vs 850 nm on many sensors |
| Illumination range | Often longer useful range at same drive power | May need more optical power for equivalent SNR |
| Common applications | Facial recognition, CCTV, machine vision, general NIR imaging | Covert surveillance, DMS, consumer devices hiding IR fill light |
| MANULED parts | IR850 and nearby family members | IR940, IR950 for deeper covert NIR |
Practical selection process
- Plot your image sensor quantum efficiency from 800–1000 nm.
- Decide whether end users must not see the illuminator (favor 940 nm).
- Build two boards with the same optics and compare SNR at your target range.
- Confirm thermal design and drive current against the MANULED datasheet.