Industrial

The Near and Short-Wave Infrared (NIR and SWIR) wavelength bands are valuable tools for modern quality control of industrial processes such as monitoring incoming materials, detecting defects, and sorting good materials from bad. Examples are many, from sorting bruised apples away from good ones, to grooming rocks from grains; Also, for watching moisture levels in crops, or in processed foods, or moisture uniformity in paper and textile production. The dark appearance of water in SWIR images due to chemical absorption makes it easy to monitor liquid fill levels inside opaque detergent and pharmaceutical bottles, or to recognize when the wrong chemical was used in medicines. Money is saved daily in fabrication plants by rejecting silicon ingots with voids or carbon deposits, checking alignment of pattern layers in integrated circuits (ICs) and Micro-Electromechanical Systems (MEMS). Steel mills and hot bottle molding plants use SWIR wavelengths to watch their manufacturing operations to control quality and optimize production.

NIR-SWIR imaging is like visible camera imaging in recording the distribution of reflected light, making it easier on operators to understand their images compared to those of the mid- or long- wave infrared (MWIR and LWIR) cameras. However, NIR-SWIR can see under the surface layer of paints and film that are opaque to visible cameras and to the human eye. It can also see-through glasses and plastics that block MWIR and LWIR cameras. NIR-SWIR cameras also have Size, Weight, and Power, plus cost advantages over the MW and LW (low SWaP+C). For chemical and hyperspectral imaging, NIR-SWIR InGaAs cameras have even QE sensitivity, linearity, and dynamic range advantages plus longer reliability over Colloidal Quantum Dot sensors as well as the same advantages over MW and LW cameras, along with lower lifetime costs.

For your applications, check out the SciCam1280 from Princeton Infrared Technologies (PIRT). This is a research grade 2-D imaging tool with the on-board cooling capability to image the weakest light levels, but also with valuable image dynamic range and great linearity over that same range. The PIRT MVCam is a compact camera for use in tight quarters while also delivering fast frame rates, dynamic range, and linearity. Both megapixel cameras provide high-definition images with large field of view (FoV) and 12-m resolution. For imaging continuous processes or for high resolution scanning, use the 1-D PIRT LineCam12 linescan camera. It is easy to synchronize with the scanner motor or microscope stage for accurate dimension control of the image.

Agricultural Inspection Using SWIR Camera Technology

Broad band light is used to image four chemicals. All four chemical looks like clear liquid in the visible. Using broad band SWIR light one can see light is absorbed differently leading to the chemicals appearing different (darker or lighter).

Chemical Detection Using SWIR Cameras

In the visible band image to the right, the coffee beans, rocks, and twigs are all brown or are dark in color on a black background. Under 1400-nm light, the coffee beans are very reflective, while the other objects are not, which enables the system to eliminate the contaminants easily.

Contaminant Detection Using SWIR Camera Technology

In the example at the right one can image nearly as well with the 1.3Mpixel SWIR image versus the >5Mpixel image in the visible and this was a clear day. In hazy conditions the SWIR improves dramatically. Imagery was taken with the 1280SciCam using a 25mm f/1.4 Optec lens which mostly transmits from 900 to 1700 nm.

Imaging Through The Atmosphere Using SWIR Cameras

One can even ‘see’ the difference between oil and water while both are on a grey steel background, as illustrated by the images on this page.

Moisture Detection Using SWIR Cameras

SWIR camera on a microscope looking at a silicon wafer

Semiconductor Inspection Using SWIR Cameras

SWIR cameras also ‘sees’ reflected ambient light as well as the object’s thermally emitted light, enabling one to more easily differentiate objects. In this case one can see the electrical cords from the soldering iron and to also see the 1.3-μm light in the integrating sphere on the left of the image.

Thermal Imaging Using SWIR Camera Technology