In the 1970s, remote sensing was a field that was almost entirely developed for defense applications. This field consisted in constructing techniques that would provide as much information as possible on an object or environment. Particular examples include distinguishing a camouflaged tank/C-130 aircraft from foliage or dehazing images of a haze-affected environment. 

These immense scientific efforts highlighted and synthesized a new imaging technique. This new technique consisted in placing one color filter and one polarizer in front of a camera. It was discovered then that by rotating the polarizer at different angles, in other words measuring different polarization angles, and by using different color filters, information on the make-up of objects in captured images could be retrieved. Such an instrument had never previously been developed. These results marked the beginning of spectropolarimetric imaging. 

Most unfortunately, this technique could not be applied to dynamic environments since color and polarization changes with the movement of objects. Indeed, a camera that could image different polarizations and different colors in one snapshot was necessary. This, however, was an unachievable goal at the time since the technology to develop such a camera module was not available. It remained though that this technique’s clear barriers still offered advantages over current imagers and therefore ‘silently’ expanded to numerous other pivotal applications. 

In point of fact, hundreds of cancer research papers centered on enhanced sensing of cancer cells with spectropolarimetric imaging have been published. Also, since the 1970s, NASA has published several works that not only demonstrate their use of spectropolarimetric satellite imaging for enhanced sensing of aerosols but also show the development of multiple different spectropolarimetric imaging systems. Indeed, since a compact spectropolarimetric camera is hard to achieve, mostly due to low polarization extinction ratios (PER), spectropolarimetric systems consist of a very bulky device made of 30+ optical components including rotating mirrors, half-wave plates and polarizers. It comes as no surprise that such a device requires heavy engineering to compensate for intense vibrations in launching into space but also when colliding with objects in orbit. 

At Metahelios we believe that the development of a compact, highly efficient spectropolarimetric camera will not only improve results for known applications of spectropolarimetric imaging, but also yield new applications of spectropolarimetry. In doing so our goal is to improve satellite imaging for ‘net-zero’ and defense, improve cancer research and even perhaps certify spectropolarimetric imaging for early diagnosis of cancer, and create opportunities for a large range of other applications. 

Our team at Metahelios is at your disposal regarding any questions: