MidOpt - Bi940 Near-Infrared (IR) Interference Bandpass Filter

The MidOpt Bi940 Near-Infrared (IR) Interference Bandpass Filter is commonly used with IR LED or laser diode illuminators. The Bi940 features a much narrower band design compared to the BN940, which can be beneficial when used in applications where ambient light conditions might otherwise create poor contrast. The Bi940 is frequently used in night vision, security, traffic control, license plate recognition and industrial inspection applications. Near-IR (NIR) image sensors used together with 940nm illumination are also being used to support iris recognition in biometrics. When used as a secondary scanner (simultaneously with a primary, mobile scanning unit), the invisible 940nm band can help improve finger-vein identification protocols. This technology identifies specific individuals using a distinct blood vessel pattern inside one’s hand. Use of a narrow band Bi940 filter can maintain imaging consistency if there are unexpected changes in ambient / background light. MidOpt Bandpass Filters have a broad, Gaussian passband to mimic and accommodate the entire output of the most common LED wavelengths, are double-side polished for exceptional parallelism and optical flatness and are anti-reflection (AR) coated to limit glare and minimize reflection loss.