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SWIR Cameras for Every Inspection, Lab and Long-Range Job
High-performance SWIR cameras for food and recycling sorting lines, semiconductor and solar inspection, research and life-science labs, and long-range surveillance. See moisture, through silicon and past haze, from compact inline cameras to deep-cooled scientific models.
What SWIR imaging sees
Light just past the edge of the visible
Short-wave infrared sits between the near infrared that ordinary cameras can just reach and the thermal bands that show heat. A SWIR camera still works with reflected light, much like a black and white visible camera, so its images look familiar and keep fine surface detail. What changes is how materials behave: some that look identical to the eye separate cleanly, and some that block visible light let SWIR through.
Silicon image sensors stop responding at around 1,000 to 1,100 nm, so SWIR cameras use materials such as indium gallium arsenide (InGaAs) that keep absorbing light out to 1,700 nm and beyond.
Where SWIR sits in the spectrum
Approximate response of common detectors, in nanometres. Dashed lines mark common laser lines and water absorption bands.
Ranges are approximate and vary by sensor design. Faded ends show where response tails off. Check the quantum efficiency curve of the exact camera you are considering.
Water and moisture
Water absorbs strongly near 1,450 nm and 1,940 nm, so wet areas, moist product and liquids look dark. That reveals moisture in grain, paper, wood and coatings, bruises under fruit skin, and liquid levels inside containers.
Through silicon and some plastics
Silicon turns transparent beyond about 1,100 nm, so a SWIR camera can look through wafers and bonded stacks. Many plastics, inks and dyes are partly transparent too, which allows fill-level checks through opaque bottles and inspection under some coatings.
Through haze
Fine haze and light smoke scatter longer wavelengths less, so long-range SWIR images often hold more detail than visible ones on a hazy day. SWIR cameras can also use night sky glow, the faint natural infrared light of the upper atmosphere, for low-light imaging.
Laser spots
Lasers at 1,064 nm and 1,550 nm, used in materials processing, rangefinding, lidar and telecom, show up clearly to a SWIR camera. Silicon cameras see 1,064 nm only weakly and 1,550 nm not at all.
Material differences
Materials that share a visible color, such as different polymers, sugar and salt, or genuine and imitation products, often reflect SWIR light differently. That contrast is the basis of SWIR sorting and hyperspectral imaging.
Behind glass, and very hot objects
SWIR light passes through ordinary glass, so cameras can work behind windows, which long-wave thermal cameras cannot. Very hot objects such as molten glass and metal give off enough SWIR light of their own to be imaged directly.
SWIR compared with visible and thermal cameras
| Visible | SWIR | Thermal (long-wave IR) | |
|---|---|---|---|
| Wavelength | About 400 to 700 nm | About 900 to 1,700 nm, extended to about 2,500 nm | About 8 to 14 µm |
| What it detects | Reflected light | Reflected light | Heat given off by objects |
| Typical sensor | Silicon CMOS or CCD | InGaAs, quantum dot or germanium on silicon | Microbolometer |
| Needs light | Yes | Yes: sun, night sky glow, halogen or SWIR LEDs | No |
| Sees through ordinary glass | Yes | Yes | No |
| Typical jobs | Color, print, dimensions | Moisture, sorting, through-silicon, haze, lasers | Temperature, heat loss, detection in darkness |
Sensor technologies
The sensor material decides what the camera sees
The detector material sets a SWIR camera's wavelength range, noise, resolution and cost. Indium gallium arsenide is the established choice. Newer approaches build SWIR sensitivity directly onto silicon readout chips, which opens the door to higher pixel counts and volume production.
Whatever the material, read the quantum efficiency curve, the dark current at the operating temperature, and the defective-pixel specification on the datasheet rather than relying on a headline wavelength range.
Standard InGaAs
An indium gallium arsenide photodiode array bonded to a silicon readout circuit. The standard composition responds from about 900 to 1,700 nm with high quantum efficiency across the band, and it is the workhorse of industrial and scientific SWIR cameras.
Visible-extended InGaAs
Removing the substrate layer that absorbs short wavelengths lets InGaAs respond down into the visible, so one camera covers roughly 400 to 1,700 nm. Useful when the same scene needs visible and SWIR detail.
Sony SenSWIR InGaAs sensors
These sensors join the InGaAs layer to the silicon readout with copper-to-copper connections instead of bump bonds. That allows a smaller pixel pitch and a response from visible light through the SWIR, and the sensors are built into cameras from a number of manufacturers.
Extended InGaAs and other eSWIR materials
Changing the InGaAs composition pushes the cutoff out to about 2.2 or 2.5 µm, and mercury cadmium telluride is also used in this range. Expect higher dark current and more cooling than standard InGaAs.
Colloidal quantum dot sensors
A film of tiny semiconductor crystals, often lead sulfide, coated directly onto a silicon readout chip, with the dot size setting the wavelength response. Building the sensor in one piece suits high pixel counts and volume production, generally trading some sensitivity and noise performance against InGaAs.
Germanium-based sensors
Germanium grown on silicon can be produced in CMOS fabs and responds into the lower part of the SWIR band, in many designs including the 1,550 nm laser line. Dark current is typically higher than InGaAs, so these sensors suit short exposures and active illumination.
Camera types
Area-scan, line-scan, cooled and OEM
SWIR cameras differ in how they build an image, how hard they cool the sensor, and how they are packaged. The right one follows from what moves, how much light there is, and where the camera has to live.
Area-scan SWIR cameras
A two-dimensional sensor captures a full frame with each exposure, just like a standard machine vision camera. Area-scan SWIR cameras handle part and package inspection, wafer and solar cell inspection, surveillance, laser work and laboratory imaging.
- Common sensor formats include 320 x 256, 640 x 512 and 1280 x 1024 pixels.
- Windowing a smaller region of interest raises the frame rate for fast events.
- Built as compact machine vision cameras, rugged outdoor housings and benchtop scientific cameras.
Line-scan SWIR cameras
A single row, or a few rows, of InGaAs pixels builds the image one line at a time as product moves past. Line-scan cameras suit continuous webs, wide belts and the free-falling product inside sorting machines, and linear InGaAs arrays are also the detectors in many NIR spectrometers.
- Image length is unlimited; resolution across the belt is set by the pixels in the row.
- Line rate is matched to belt or fall speed, with an encoder where speed varies.
- Needs a bright, even line of SWIR illumination across the whole field.
Uncooled and temperature-stabilized
Cameras without active cooling, or with a thermoelectric element that only holds the sensor at a steady temperature. Compact and lower power, they suit bright scenes and short exposures on inspection lines and in OEM devices, and rely on correction tables that track sensor temperature.
TEC-cooled
A thermoelectric (Peltier) cooler holds the sensor below ambient to cut dark current and noise. The usual choice for longer exposures, low light, and measurements that need stable results over a full shift.
Deep-cooled scientific
Multi-stage thermoelectric or liquid-assisted cooling keeps the sensor far below ambient for long exposures in spectroscopy, astronomy, photoluminescence and NIR-II fluorescence imaging. Built for low noise rather than speed.
OEM camera cores
Board-level camera modules without a full housing, for integrators who build SWIR imaging into gimbals, handheld devices, sorting machines and instruments. Usually supplied with a development kit and documented interfaces.
Applications
Where SWIR cameras earn their place
Any job where water, silicon, plastics, haze or an infrared laser gets in the way of a visible camera is a candidate for SWIR imaging, from production lines to research labs.
Food and agriculture sorting
Finding bruises, foreign material, shell fragments and moisture differences in nuts, grains, fruit and vegetables at full line speed, often inside optical sorting machines.
Moisture and fill-level inspection
Seeing water content in paper, wood, textiles, coatings and food, and checking liquid levels through opaque plastic containers.
Plastics recycling sorting
Identifying polymer types by their SWIR absorption features so mixed waste can be separated by air jets on the belt. Carbon-black plastics absorb SWIR light and remain a known difficulty.
Semiconductor and solar wafer inspection
Looking through silicon for voids, cracks and bonding defects in wafers and stacked devices, and imaging the luminescence of silicon solar cells to find cracks and inactive areas.
Pharmaceutical packaging
Checking tablets and capsules through some plastic films, verifying fill, and spotting moisture or coating differences that look the same in visible light.
Surveillance and long-range imaging
Seeing farther through haze and light smoke, working behind glass and detecting laser spots, on border, coastal, port and perimeter cameras, often alongside visible and thermal sensors.
Laser beam profiling
Imaging and measuring beams from 1,064, 1,310 and 1,550 nm lasers used in telecom, materials processing and lidar, where silicon cameras are weak or blind.
Spectroscopy and hyperspectral imaging
Linear and area InGaAs arrays are the detectors in NIR spectrometers and SWIR hyperspectral cameras, which measure the chemical makeup of food, pharmaceuticals, minerals and plastics.
Life-science and NIR-II imaging
Fluorescence imaging in the second near-infrared window, roughly 1,000 to 1,700 nm, where tissue scatters less light than at visible wavelengths, used in preclinical research and microscopy.
Choosing a SWIR camera
What to settle before you request a quote
| Factor | What it decides |
|---|---|
| Wavelength range | Standard InGaAs covers about 900 to 1,700 nm. Choose visible-extended if you also need visible detail, and extended SWIR only if the features you need lie beyond 1,700 nm, since it adds noise and cooling. |
| Resolution and pixel pitch | Pixels across the field of view set the smallest defect you can resolve. Smaller pixels fit more resolution on a sensor and allow smaller lenses; larger pixels collect more light each. |
| Frame rate or line rate | Match it to line speed or the event you need to capture. Many cameras raise frame rate when you window a smaller region of interest. |
| Noise and dark current | Read noise matters for short, dim exposures; dark current grows with exposure time and temperature. Compare datasheet figures measured under the same conditions. |
| Cooling | Uncooled or stabilized for bright scenes and short exposures, TEC-cooled for longer exposures and stable measurements, deep-cooled for long scientific integrations. |
| Dynamic range | Scenes with bright reflections next to dark areas need wide dynamic range. Many SWIR cameras offer selectable gain modes or high dynamic range readout. |
| Non-uniformity correction | InGaAs pixels vary in offset and gain, and a few may be defective. Check that the camera applies factory correction suited to your sensor temperature and exposure range, and how it replaces defective pixels. |
| Interface | GigE Vision for long cables and multi-camera systems, USB3 Vision for simple setups, CoaXPress or Camera Link for high data rates through a frame grabber. |
| Lens and lighting | Plan a SWIR-corrected lens and SWIR illumination with the camera. A visible-only lens or white LED lighting can make a good camera look poor. |
| Export controls | Some SWIR cameras, sensors and cores are export controlled, for example under the US EAR, and products designed for military use can fall under ITAR. Ask the supplier for the classification of the exact model and allow time for any licence. |
Camera interfaces
Most industrial SWIR cameras follow the GenICam standard, so their settings work the same way across common machine vision software whichever link they use.
GigE Vision
Standard Ethernet cabling, long cable runs and straightforward multi-camera networks, with Power over Ethernet on many cameras.
USB3 Vision
A direct connection to a PC over short cables, convenient for lab benches, prototypes and compact systems.
CoaXPress
High data rates over coaxial cable into a frame grabber, for fast line-scan and high-resolution area-scan cameras.
Camera Link
An established frame-grabber interface still found on many line-scan and scientific cameras and in existing systems.
Lenses and lighting
Setting up a SWIR system, step by step
Lenses designed for visible light can lose transmission and focus differently in the SWIR, and white LEDs give off almost no SWIR light. The camera, lens, filter and light source have to be chosen together.
- 1Test real samples under SWIR light first, ideally with the supplier, to confirm the contrast you need actually appears.
- 2Pick the wavelength band. If a narrow band, such as the 1,450 nm water band, carries the contrast, plan a bandpass filter or matching LEDs.
- 3Choose the sensor format and pixel count from the field of view and the smallest feature you must see.
- 4Select a SWIR-corrected lens that matches the sensor size, pixel pitch and working distance.
- 5Design the lighting: halogen for a broad spectrum, SWIR LEDs for specific bands, with diffusers or line lights to suit the geometry.
- 6Load the correction tables, then validate with known good and bad samples before going live.
Keeping image quality consistent
- Keep the camera at a steady operating temperature, or use correction tables matched to temperature, because InGaAs offset drifts with heat.
- Let lamps and cameras warm up before taking reference images or calibrating.
- Check the rated wavelength range of every lens and window in the light path.
- Watch for stray light from windows and halogen sources. Sunlight carries a lot of SWIR.
- Re-check flat-field and defective-pixel correction after changing exposure, gain or cooling settings.
- Keep lenses and protective windows clean on line installations; dust and residue scatter SWIR light too.
Eye safety: SWIR illuminators and lasers are invisible, so the usual warning of a bright light is missing. Wavelengths beyond about 1,400 nm are often called eye-safer because the front of the eye absorbs them before they reach the retina, but high power can still cause injury. Follow the laser and lamp safety rules that apply to your source.
Information only. The guidance on this page is general and educational. It is not engineering, optical, laser safety or export compliance advice and does not replace the manufacturer's instructions and datasheets, applicable standards and regulations, or a qualified professional. Verify all information before relying on it. Read the full disclaimer.
FAQ
SWIR camera questions
What is a SWIR camera?
A SWIR camera images short-wave infrared light, the band just beyond what silicon image sensors can detect. Most use an indium gallium arsenide (InGaAs) sensor. Like a visible camera, it forms its picture from reflected light, so the images look like black and white photographs, but materials such as water, plastics, silicon and some inks look very different from how they appear to the eye.
What wavelength range does SWIR cover?
Definitions vary, but SWIR is usually taken as roughly 900 to 1,700 nm for a standard InGaAs camera, which is set by the cutoff of the InGaAs material itself. Extended SWIR cameras push the long end out to about 2.2 or 2.5 µm. Some InGaAs sensors are also built to respond down into the visible range, so one camera covers visible and SWIR light.
How is a SWIR camera different from a thermal camera?
A thermal camera (long-wave infrared, about 8 to 14 µm) sees heat given off by objects, so it works in total darkness and shows temperature differences. A SWIR camera sees reflected light, so it needs light from the sun, the night sky, halogen lamps or SWIR LEDs, and it shows surface detail and material differences rather than temperature. SWIR light also passes through ordinary glass windows, which block long-wave thermal imaging. Only very hot objects, such as molten glass or metal, give off enough of their own light to show up in SWIR.
Why can't a normal camera see SWIR light?
Standard CMOS and CCD sensors are made of silicon, which becomes transparent to light beyond about 1,100 nm and loses most of its sensitivity well before that. Light in the SWIR band passes straight through a silicon sensor without being detected. SWIR cameras use materials that absorb at those wavelengths, most often InGaAs, or newer options such as quantum dot films and germanium on silicon.
Why does water look dark in a SWIR image?
Water absorbs strongly in bands near 1,450 nm and 1,940 nm, with weaker bands at shorter wavelengths. Anything containing water, such as wet patches, bruised fruit, moist grain or a liquid inside a container, absorbs more light in those bands and appears darker. This is why SWIR cameras are used for moisture checks, fill-level inspection and food sorting.
What can a SWIR camera see through?
Depending on the material and thickness, SWIR light passes through silicon, many plastics, some paints, coatings and dyes, ordinary glass, and haze or light smoke better than visible light does. That allows inspection through silicon wafers, fill levels through opaque plastic bottles, and clearer long-range views in hazy air. It does not see through metal, thick fog or walls, and results always need to be tested on the actual material.
Do SWIR cameras need special lenses?
Usually, yes. Lenses designed for visible light can lose transmission and focus differently in the SWIR because their coatings and color correction are optimized for shorter wavelengths. SWIR-corrected lenses use coatings and glass designs suited to the band the camera covers, and they should match the sensor size and pixel pitch. Standard mounts such as C-mount are common.
What lighting works with SWIR cameras?
Light sources that emit in the SWIR band. Sunlight and halogen or other incandescent lamps contain a lot of SWIR light. SWIR LEDs are made at specific wavelengths, commonly around 1,050, 1,200, 1,300, 1,450 and 1,550 nm, and are used when a particular material contrast is needed. White LEDs and fluorescent lights emit very little SWIR light, so they are a poor choice for SWIR imaging.
Does a SWIR camera need cooling?
It depends on the exposure time and the noise you can accept. Dark current in InGaAs rises steeply with temperature, so short exposures on a bright inspection line often work with uncooled or temperature-stabilized cameras, while long exposures in spectroscopy, astronomy or NIR-II fluorescence imaging usually call for thermoelectric cooling or deep-cooled scientific cameras. Extended SWIR sensors typically need more cooling than standard InGaAs.
What is extended SWIR?
Extended SWIR (eSWIR) cameras respond beyond the roughly 1,700 nm limit of standard InGaAs, out to about 2.2 or 2.5 µm. They use InGaAs with a different composition or other materials such as mercury cadmium telluride. The extra range reaches more absorption features of plastics, minerals and chemicals, at the cost of higher dark current and usually more cooling.
Are SWIR cameras subject to export controls?
Some are. Depending on their specifications and design, certain SWIR cameras, sensors and camera cores are controlled under export regulations, for example the US Export Administration Regulations, and products designed for military use can fall under ITAR. Many other SWIR cameras are not controlled. Ask the supplier for the export classification of the exact model and allow time for any licence if it will cross borders.
What should I send to get a quote?
Describe the application, the material or scene you need to see, the wavelength range, the resolution and frame rate, whether it is an area-scan or line-scan job, the interface your system uses, the quantity and your timeline. If you have sample images or know the working distance and field of view, include those too. That is enough for a supplier to suggest a camera, lens and lighting and come back with a quote.
Request a quote
Get a SWIR camera quote
Whether you need one camera for a lab bench or a set for a production line, tell us the application, the wavelength range, the resolution and the quantity, and you will get a quote back.
- Area-scan and line-scan SWIR cameras
- Uncooled, TEC-cooled and deep-cooled scientific cameras
- OEM camera cores, SWIR lenses and illumination