Small image sensors continue to improve in cost and performance and have become ubiquitous in smart phones, notebook computers, tablets and many other devices. At the same time new device types such as headsets, glasses, dashboard cameras, and autonomous vehicles continue to emerge. The common CMOS (Complementary Metal Oxide Semiconductor) image sensor that is used in most digital cameras has an array of photodetectors. Usually there is one photodetector for each pixel. The sensor is well suited to capture and measure visible light.
The same image sensor is also able to capture and measure ultraviolet and NIR (Near Infrared) light. As a result, new applications are being developed to exploit these properties. Imaging applications extending the range of spectral sensitivity beyond the visible range are coming to market. In addition to applications extending sensitivity to the NIR spectrum, hyperspectral cameras and multi-spectral cameras are coming to market that extend the sensitivity into the UV spectrum for applications ranging from chemical composition analysis, to detecting fruit ripeness, to detecting the correct application of sunscreen.
Hyperspectral image sensors have been developed using a common underlying photodetector element that is often optimized for the visible spectrum due to the large focus on visible photography.
Imaging applications extending the range of spectral sensitivity beyond the visible range are coming to market. These applications include face recognition, iris scanning, and multi-spectral imaging for analyzing chemical content to name a few examples.