Measurement Of Filters Used In Night Vision Applications

Measuring transmission filters used in night vision-compatible environments demands a spectrometer system sensitive to very low light levels over a broad dynamic range, from 0.001% to 90%. The Ocean Optics QE65000-ABS preconfigured system is optimized for this task, offering a high signal-to-noise ratio, low stray light, and good optical resolution from the UV through NIR.

The human eye is designed for daylight use and is most sensitive from 380 to 780 nm. Night vision goggles and imaging systems work by gathering and amplifying near infrared light by up to 2000x —using image intensifiers and optics, thereby extending the spectral and dynamic range of our vision.

Night vision is an essential tool for law enforcement and the military. Night vision devices (NVDs) used within vehicles are very sensitive to NIR light emitted by lighting and displays inside the vehicle. If not properly filtered, ambient NIR light can reduce the sensitivity of NVD to objects outside the vehicle. Night vision compatibility (NVC) filters are incorporated as a window on displays or light sources, reducing the NIR emission of these devices by as much as 105 times in the 600 to 930 nm range. Transmissions at shorter wavelengths need to be as high as possible to maintain visibility for users not wearing NVDs.