innovation for industry
Optics and photonics
Leti, a CEA Tech institute, recently demonstrated that curved sensors reduce the form factor of optical lens blocks and, thus, of camera modules. The institute's new Pixcurve curved sensor was showcased at the latest edition of the Photonics West trade show in conjunction with LAM (the Marseille Astrophysics Laboratory). Currently, imaging systems are made up of optical lens blocks combined with a silicon sensor. But, because silicon wafers are planar, the sensors are, too. This requires a set of lenses to create a flat focal plane compatible with the flat sensor.
Which is where the idea of curving the sensors—just like the human retina and other biological "sensors"—came from. The researchers decided to fabricate the component on silicon. They started by grinding the substrate down to make it thinner, successfully obtaining a thickness of less than 100 microns (down from 725 microns originally). The thinner sensor is flexible and can be placed on a curved structure in a conventional enclosure.
The flexible sensor eliminates the need for a number of lenses, for a more compact optical lens block. For identical image quality, the system is half the size of conventional optical blocks. The fabrication process, protected by several patents, also offers the advantage of being easy to integrate into current production lines.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.