Near-Infrared (NIR) Cameras with High Sensitivity in Low Light

What makes NIR cameras unique?

“Near-infrared” (NIR) is the portion of the electromagnetic spectrum directly adjacent to the visible range - making it invisible to the human eye. NIR-optimized industrial cameras are popular for applications that need to utilize this wavelength range, including applications with poor light conditions such as traffic monitoring. Until now, these applications were only possible with infrared cameras with expensive CCD sensors.

CMOS technology can do the job, providing sensors with increased sensitivity in the near-infrared range over 850 nm. This is achieved through the application of a thicker substrate layer (as compared to a monochrome sensor) for an increase in NIR sensitivity. Thanks to CMOS technology, industrial cameras with excellent sensitivity are available at attractive prices and are already firmly established in the machine vision market.

NIR-optimized cameras, such as those with Sony's 3.2 MP IMX900 or 12.5 MP IMX676 sensors, OMNIVISION's 5 MP OG05C sensor, or e2V's 1.3 MP EV76C661 sensor still manage quantum efficiencies close to 40% in the 850 nm range. Compared to non-NIR-optimized sensors, this represents a doubling of the sensitivity value at this wavelength.

Do I need an NIR camera for my application?

Some application fields and inspection solutions require NIR for high wavelengths as well as for normal lighting, to record high-contrast images. Standard industrial cameras quickly reach their limits in that particular scenario, since they require very good lighting conditions to capture useable images. Setting up these light solutions adds tremendous cost and complexity, which in turn leads to rising system costs and deterioration of the price/performance ratio. Industrial cameras with NIR-optimized sensors greatly simplify life for manufacturers facing inspection tasks of this type.

Typical application examples are traffic monitoring installations that need to work in poor lighting conditions and at night, fruit and vegetable inspections to detect damaged spots using location-sensing spectroscopy, and the inspection of solar wafers through electro-luminescence.