The infrared (IR) part of the spectrum is defined as electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves
For camera technology, IR is commonly divided into 3 main sections as shown below:
1. Short Wave IR: 0.9 to 2.5µm
2. Mid Wave IR: 3-5µm
3. Long Wave IR: 8-12µm
Short Wave Infrared Radiation can only be detected by dedicated sensors, such as InGaAs. It has to be pointed out that, although light in the shortwave infrared region is not visible to the eye, this light interacts with objects in a similar manner as visible wavelengths. Therefore, images from an InGaAs camera are comparable to visible images in resolution and detail.
One major benefit of SWIR imaging is the ability to image through haze, fog and glass. SWIR detector can also be used in conjunction of pulsed eye safe laser (1.55 µm) and this makes it the ideal detector for Active Imaging.
SWIR technology can be used in the following applications: