IDTechEx Compares SWIR Imaging Technologies

PRNewswire: IDTechEx publishes a comparison of SWIR technologies:

"Arguably the most compelling attribute of imaging in the SWIR region is the reduced optical scattering of longer wavelengths of light. Reduced scattering means that SWIR cameras on vehicles and drones can see through fog and dust clouds, greatly improving visibility and hence safety.

Another benefit of SWIR imaging is distinguishing visually similar materials, which may have similar absorption (and thus reflection) spectra in the visible region but significant differences in the SWIR region. This ability is highly valuable for applications such as quality control in industrial processes, where it enables unwanted items such as rocks and metals to be spotted in food production for example, and sorting recycling.

Other benefits include thermal imaging for items with temperatures between 200 and 500 C, and the ability to see through materials that are opaque to visible light but transparent to SWIR. Silicon is a great example of this, with SWIR imaging used to check the quality of wafer attachment.

...at present short-wave infra-red (SWIR, 1000-2000 nm) imaging is dominated by expensive InGaAs (Indium Gallium Arsenide) sensors that can absorb light up to around 1800 nm. These can cost upwards of $10,000 due to the expense of producing the InGaAs layer via vapor deposition, low manufacturing yields, and limited pixel density that increases material consumption for a given resolution relative to standard silicon photodetectors.

The combination of commercially desirable attributes and an expensive incumbent technology creates a clear opportunity for a disruptive, low-cost alternative. As such, multiple competing approaches for SWIR imaging are being developed."