How smartphones will disrupt the SWIR imaging industry

By Axel Clouet, PhD. and Eric Mounier, PhD., both at Yole Intelligence, part of Yole Group, for EETIMES – Unprecedented changes in the SWIR industry are happening, with the emergence of new technologies and the entrance of game-changing players who may enable market and technology disruption.

Short-wave infrared (SWIR) refers to a portion of the electromagnetic spectrum between 1 µm and 3 µm. Today, most of the imagers used in everyday life operate in the visible and near-infrared range (0.4 µm to 1 µm) and are based on silicon technology. Sensing SWIR radiation requires imagers based on other materials, making them orders of magnitude more expensive than silicon-based imagers. Therefore, SWIR’s use today is limited to specific applications in defense, industry, or research.

SWIR’s physical properties are of such appeal to the consumer market, however, that this primarily defense-oriented technology is knocking on the door of the smartphone industry.

In defense, SWIR is used for target designation, ranging, or acquiring images under harsh conditions such as through smoke, in bad weather, and over long distances at night. In industry, it is used in semiconductor manufacturing to inspect metallic contacts or detect cracks in solar cells. SWIR also enables the monitoring of liquid or powder levels through some plastic containers that are opaque in the visible spectrum but transparent in SWIR. These wavelengths are also interesting for sorting applications, as materials in waste, plastics, textiles, and even food have identifiable spectral signatures in this band.
SWIR wavelengths would have a significant advantage over near-infrared (NIR) in consumer 3D sensing modules. Smartphone makers battle to increase the screen-to-body ratio and hide sensors under the screen. The main motivation for SWIR in 3D sensing is to integrate facial-recognition modules behind the OLED display, as these materials are more transparent in the SWIR band.

Eye safety regulations also authorize more powerful illumination sources in SWIR, which is helpful for increasing reliability and detection range in augmented-reality applications. And in automotive, SWIR is attractive for advanced driver-assistance systems (ADAS), in which it would allow more stable image acquisition under harsh conditions and be able to combine 2D and 3D imaging in one system.

This pull from the consumer market is inspiring unprecedented changes in the SWIR industry, with the emergence of new technologies and the entrance of game-changing players who may enable market and technology disruption.

Evolution of SWIR imaging

Most of the current SWIR imagers integrated into cameras rely on indium gallium arsenide material. InGaAs technology was originally developed for the defense market and then expanded into industrial imaging. InGaAs is currently the best technology in terms of performance and reliability, but it will be challenging to scale up manufacturing processes and sufficiently decrease costs to address other segments… Full article.

Source: EETIMES.