The central wavelength is 940+/-2nm, the half bandwidth is 20+/-2nm, it can efficiently transmit infrared light in the target band (930-950nm) and significantly reduce the interference of ambient light
The transmittance at the central wavelength of 940nm is >90%, which can retain the effective signal strength to the greatest extent, and is suitable for low-light or long-distance detection scenes
The cut-off depth is OD4 in the range of 200-1700nm outside the passband, completely blocking visible light and near-infrared stray light

940nm Bandpass Filter FWHM 20nm Technical Datasheet

Parameter	Specification
Center Wavelength (CWL)	940 nm ± 2 nm
FWHM	20 nm ± 2nm
Peak Transmission	≥ 90%
Blocking Range	200 – 1700nm
Optical Density (OD)	OD4
Angle of Incidence (AOI)	0°
Clear Aperture	>90% of the diameter
Substrate Material	UV Fused Silica, K9,sapphire, Other optical glass
Size	Ø12.7mm, Ø25.4mm,Ø50.8mmor customizable
Environmental Durability	Compliant with MIL-STD-810G
Other available wavelength	940/10nm,940/40nm,940/30nm,940/50nm,940/60nm,940/70nm,940/80nm
Custom Option	EUV to 30,000nm
Filter Type	Multilayer Interference Bandpass Filter
Coating Technology	Ion-Assisted Deposition (IAD), Hard coated
Surface Quality	80-50, 60-40, 40-20 (per MIL-PRF-13830B

940nm Bandpass Filter FWHM 20nm Applications

Infrared sensing
The human body or object will reflect/emit infrared light in the 940nm band, but ambient light will interfere with the sensor. The 940/20nm optical filter only allows infrared light near 940nm to pass through, shielding other wavelengths, which can improve the accuracy and distance of detection
Optical communication
940nm is a common communication wavelength, but other light sources may cause crosstalk. The 940/20nm filter can isolate the 940nm signal, suppress background noise, and allow the communication system to work stably in a strong light environment
Machine vision
Plastics and silicone have characteristic absorption/reflection at 940nm, but visible light cannot distinguish them. This filter can only capture the 940nm characteristic band and enhance the contrast of the target object. Accurately identify material defects
Biometric identification
Human veins have strong absorption in the 940nm band, forming a clear image, but ambient light will reduce the contrast. The 940/20nm bandpass filter can highlight the vein/iris features and shield interfering light