Short-wave infrared (SWIR) and mid-wave infrared (MWIR) cameras are both advanced infrared imaging technologies serving different application requirements. Choosing between SWIR and MWIR depends on factors like environmental conditions, required sensitivity, wavelength range, and application requirements.1-8
Image Credit: Ignatievs/Shutterstock
SWIR: An Overview
The electromagnetic spectrum encompasses radiation bands like gamma rays, ultraviolet, visible light, infrared, and millimeter waves. The infrared is the part of the spectrum with wavelengths longer than about 0.7 µm, but shorter than about 300 µm.1
SWIR is the part of the electromagnetic spectrum from the point where the response of the silicon detector falls off to the beginning of the MWIR atmospheric transmission window/1 to 3 µm wavelength range.1
This range, similar to visible light, primarily responds to reflected light from objects rather than their thermal emissions. Thus, SWIR serves unique applications that benefit from illumination by invisible sources, spectral signatures from molecular vibrations, or the reduced scattering of longer wavelengths.1
Various detectors, such as indium gallium arsenide (InGaAs), mercury cadmium telluride (MCT or HgCdTe), and germanium, are used for these SWIR applications. Among them, InGaAs array detectors are most suitable for industrial imaging applications owing to their high quantum efficiency and low dark current at room temperature.1
Common SWIR Camera Applications
SWIR imaging/0.9–1.7 µm produces monochromatic, high-resolution images with high contrast and distinct shadows. Specialized InGaAs sensors are a high-performance, cost-effective solution for SWIR imaging in industrial applications.2,3
This advanced technology enables novel approaches to quality assurance, such as temperature detection, precise material differentiation, and subsurface imaging. SWIR imaging often relies on specialized InGaAs sensors for optimal performance in industrial applications.2,3
Objects emitting infrared radiation at temperatures of 140 °C and above can be detected using SWIR technology. Thus, SWIR offers significant benefits for process monitoring by enabling contactless temperature measurement of products and materials. This is useful where conventional temperature measurement methods are ineffective or dangerous.3
Other top applications include semiconductor wafer inspection and silicon imaging, as silicon becomes transparent at SWIR wavelengths; laser beam profiling, alignment, and pulse imaging, as SWIR cameras directly image 1310 nm, 1064 nm, and 1550 nm laser sources; machine vision and industrial quality inspection; and biomedical imaging and fluorescence research.4
In manufacturing environments, SWIR imaging improves defect detection and material discrimination. SWIR cameras are used for target identification and long-range observation for security purposes.4
Additionally, researchers utilize SWIR imaging to reduce scattering and improve contrast. In photovoltaic materials, SWIR imaging reveals non-uniformities and defects, enabling efficient inspection of solar cells and energy materials.4
MWIR: An Overview
The MWIR, a part of the infrared band of the electromagnetic spectrum, covers wavelengths ranging from 3 µm to 5 µm, where cryogenically cooled indium antimonide (InSb) and HgCdTe are used. This is the radiant heat detected by most cooled thermal imaging cameras, which is more advantageous than reflected light, as in a visible camera, for surveillance applications.1,5
No illumination is required to observe in complete darkness, enabling long-range detection of potential threats. Warm objects such as vehicles, animals, and humans become clearly visible on a colder background with thermal imaging cameras, regardless of lighting conditions.6
MWIR cooled thermal cameras achieve the longest detection range for thermal infrared surveillance cameras, as cooled thermal cameras minimize the signal noise on the sensor using a cryogenic cooler to chill the thermal core to -196 °C (-321°F).5,6
This approach is critical for longer ranges, as longer lenses are less efficient than wide-angle lenses, which results in less thermal energy reaching the sensor. The amount of noise becomes more critical at lower energy levels, which makes chilling the thermal core necessary to preserve essential detail and contrast at such extreme ranges.6
Thermal cameras are also immune to bright light, another advantage over visible cameras. Bright lights from flashlights or vehicle headlights cause light flares and overexposure in images when using standard visible cameras at night.6
This makes it difficult to observe activities and details around those lights. Thermal imaging remains unaffected under these conditions and provides a detailed, clear image around bright light sources.6
Recent Developments
A paper recently published in Applied Sciences proposed a novel approach to material classification using SWIR imaging. The approach was aimed at applications in which visually distinguishing similar objects based on material properties is crucial, such as autonomous driving.7
Results showed that the SWIR data achieved excellent classification with 99% accuracy in differentiating real from artificial objects, compared to 77% with visible spectrum data.7
In another study recently published in Optics and Lasers in Engineering, a single-pixel MWIR thermal camera was proposed and developed. The thermal image of silicone rubber-encapsulated light-emitting diode (LED) chips could be reconstructed by measuring 3.7–4.7 µm MWIR using a compressive sensing algorithm, without prior measurement of the thermoelectric coefficient of the LED chips.8
Which Technology is Right for Your Application?
SWIR and MWIR cameras serve different infrared imaging requirements. SWIR cameras, typically operating in the 0.9–1.7 µm range, primarily detect reflected radiation and are well-suited for material differentiation, semiconductor inspection, laser beam profiling, machine vision, biomedical research, and industrial quality control. SWIR can also support contactless temperature monitoring of objects at 140 °C and above.
Saving this for later? Download a PDF here.
MWIR cameras operate in the 3–5 µm range and detect radiant heat, making them effective for thermal surveillance. Cooled InSb and HgCdTe cameras can provide long-range detection, even in complete darkness, while remaining unaffected by bright lights. Therefore, SWIR is preferable for material and reflected-light applications, whereas MWIR is better suited to long-range thermal imaging and surveillance.
The Way Forward
In conclusion, SWIR and MWIR cameras serve different imaging needs. SWIR is preferable when reflected-light information and material properties are important, whereas MWIR is the better choice when detecting heat and achieving reliable thermal visibility under challenging lighting conditions.
References and Further Reading
- Hansen, M. P., & Malchow, D. S. (2008). Overview of SWIR detectors, cameras, and applications. Thermosense XXX, 6939, 94-104. DOI: 10.1117/12.777776, https://www.spiedigitallibrary.org/conference-proceedings-of-spie/6939/69390I/Overview-of-SWIR-detectors-cameras-and-applications/10.1117/12.777776.short
- Yaya, F. (2025) Understanding SWIR [Online] Available at https://www.oxinst.com/learning/view/article/understanding-swir (Accessed on 20 August 2026)
- SWIR Imaging - Applications and Technology [Online] Available at https://www.baslerweb.com/en/learning/swir/ (Accessed on 20 August 2026)
- Tack, L. M. (2026) Why Use SWIR Cameras? Top 10 Industrial, Scientific, and Machine Vision Applications [Online] Available at https://www.automate.org/vision/tech-papers/why-use-swir-imaging (Accessed on 20 August 2026)
- What is MWIR (Mid-Wave Infrared) and How Does it Relate to Thermal Imaging Cameras? [Online] Available at https://www.infinitioptics.com/glossary/mwir-mid-wave-infrared (Accessed on 20 August 2026)
- LWIR & MWIR Cameras Brochure [Online] Available at https://www.infinitioptics.com/sites/default/files/2026-01/Thermal%20Camera%20Lineup%20Brochure%204-02%20Jan2026.pdf (Accessed on 20 August 2026)
- Song, H. et al. (2024). Short-wave infrared (SWIR) imaging for robust material classification: overcoming limitations of visible spectrum data. Applied Sciences, 14(23), 11049. DOI: 10.3390/app142311049, https://www.mdpi.com/2076-3417/14/23/11049
- Hsu, Y. S., & Chung, T. Y. (2023). Single-pixel MWIR camera for acquiring thermal images of silicone rubber encapsulated LEDs. Optics and Lasers in Engineering, 161, 107343. DOI: 10.1016/j.optlaseng.2022.107343, https://www.sciencedirect.com/science/article/abs/pii/S0143816622003943
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.