La nouvelle “Minute du chercheur” présentée par Kevin Heggarty, maître de conférences au département Optique, est consacrée aux éléments optiques diffractifs, plaques de verre sur lesquelles il est possible d'inscrire des micro-structures.
Diffractive Optical Elements. At Telecom Bretagne, the micro-structures are designed using highly optimised computer algorithms developed by optics department researchers. The resulting files are sent to the department cleanrooms where they are used to write the elements into a layer of photoresist spin-coated onto a glass substrate. The write process is performed using an extremely high speed parallel-write photoplotter. Research continues with a 4th generation photoplotter to fabricate bigger, better DOEs. Nano-structures now replace micro-structures requiring ever more sophisticated design models and algorithms, but leading to gains in performance and an ever-widening field of applications.