Why Asymmetric 850nm and 940nm IR LEDs Deliver Better Performance for Surveillance, Intelligent Transportation Systems, and Smart Applications

Traditional symmetric IR LEDs often struggle with providing even lighting, frequently creating overexposed "hotspots" in the center and dark peripheral zones. Brightek's Asymmetric IR LEDs, available in both 850nm and 940nm wavelengths, solve this critical issue by their asymmetric lens design, which ensures uniform illumination across the entire frame without the need for bulky secondary lenses.

This uniform infrared light is particularly crucial for applications like Intelligent Transportation Systems, as it ensures that license plates remain readable across the entire detection zone rather than just in the center of the frame. This technology offers key benefits including better lighting uniformity, lower system costs, a more compact hardware design, and automotive-grade reliability (AEC-Q102 qualified).

Understanding the Core: 850nm vs. 940nm IR LEDs

Choosing the right wavelength is essential for optimizing system performance:

•  850nm IR LED: This wavelength produces a slight red glow that is visible to the human eye, but is ideal for high-sensitivity security cameras. It is the preferred choice when long-distance visibility is paramount.

•  940nm IR LED: Known as the "invisible" solution, this wavelength is perfect for covert surveillance, in-cabin Driver and Occupant Monitoring Systems (DMS/OMS), and facial recognition systems where human eye comfort is strictly required.

All infrared LED emitters (IR LEDs) from Brightek are eye-safety certified to IEC 62471.

The Asymmetric Advantage: Solving Traditional Limitations

Traditional IR LEDs face significant physical and optical limitations that asymmetric IR LEDs easily overcome:

•  The "Dark Zone" Problem: Traditional LEDs emit narrow, symmetric beams that naturally create shadowed corners in the camera's field of view. This makes it difficult to capture clear, actionable footage across the entire FoV.

Traditional IR LED	Asymmetric IR LED

•  Eliminating Secondary Optics: To compensate for narrow beams and uneven light distribution, traditional camera modules require extra secondary lenses to widen the beam. This workaround increases manufacturing costs, requires more physical space, and adds design complexity to the optical stack. Brightek's asymmetric IR LEDs eliminate this need entirely.

The Benefits Brightek's Asymmetric IR LEDs Deliver:

•  Uniform Illumination: The primary benefit is edge-to-edge clarity in every frame, ensuring no more shadowed corners.

•  Cost Efficiency: The technology achieves superior area coverage using fewer LEDs, which directly reduces total power consumption and overall hardware expenses.

•  Compact & Eco-Friendly Design: By eliminating the need for extra optical lenses and reducing the materials used in the optical stack, manufacturers can design much smaller and more sustainable devices.

Primary Application Scenarios

The highly precise asymmetric IR LEDs makes them ideal for a wide range of smart applications:

•  High-Performance Surveillance: They provide improved nighttime visibility for wide-angle security cameras and License Plate Recognition (LPR) systems.

•  In-Cabin DMS/OMS: They deliver reliable performance for monitoring drivers and occupants, ensuring vehicular safety without visually distracting the driver.

•  Smart Access Control: The technology enhances security for smart door locks and laptop cameras by providing the precise illumination needed for accurate facial authentication.

•  Intelligent Transportation Systems: They provide discreet, high-efficiency illumination for traffic monitoring, vehicle detection, and license plate recognition (LPR). By operating in the non-visible spectrum — commonly via 850nm IR LED and 940nm IR LED solutions — these LEDs allow cameras to capture high-contrast images at night or in low-light conditions without distracting drivers.

Brightek’s Asymmetrical IR LED Lineup

Quick-reference list of specialized series for easy indexing: