Short wavelength infrared (SWIR) refers to the portion of the infrared spectrum that encompasses wavelengths roughly between 1,000 and 3,000 nanometers (nm). In the electromagnetic spectrum, infrared radiation is categorized into different regions based on wavelength, and SWIR falls between the near-infrared (NIR) and the mid-infrared (MIR) regions.
Key points about SWIR:
Wavelength range: SWIR typically covers the wavelength range from approximately 1,000 nm to 3,000 nm. This range is often divided into two sub-regions: Short-Wavelength Infrared I (SWIR-I) from 1,000 to 1,700 nm and Short-Wavelength Infrared II (SWIR-II) from 1,700 to 3,000 nm.
Applications: SWIR radiation has various applications in imaging, sensing, and communication. SWIR cameras and sensors are employed in diverse fields, including industrial inspection, agriculture, surveillance, medical imaging, and material analysis.
Penetration through materials: SWIR radiation can penetrate certain materials more effectively than visible light, allowing for imaging and inspection of objects or substances that may be opaque in the visible spectrum. This property is useful in applications such as imaging through fog or certain types of packaging materials.
Absorption characteristics: Different materials absorb and transmit SWIR radiation in unique ways. Some materials that are opaque in the visible range may be transparent or partially transparent in the SWIR range, providing additional information for material identification and characterization.
Night vision: SWIR is often used in night vision technologies. Certain SWIR wavelengths can penetrate atmospheric conditions better than visible light, allowing for improved visibility in low-light environments.
Semiconductor materials: In the context of semiconductor devices, SWIR detectors and sensors are often made using materials like indium gallium arsenide (InGaAs) that are sensitive to wavelengths in the SWIR range.