The way to cheaper and smaller sized thermals cameras security opens the work of a group of French researchers, who developed an IR camera (thermal infrared) with a silicon lens.
The new lens, which is made of a material much cheaper than those widely used today, is as thick as a fingernail with a diameter smaller than a No.2 pencil. Although its resolution is not high, it is able to indicate the presence and some general characteristics of one person.
The researchers presented the results of their research in a paper published in the Optos Letters of OSA (Optical Society). Potential applications of this technology focus more on monitoring, allowing for the development of cheaper security systems in the long run, especially for home use.
“It could locate people in a room, or a street corner, or a dark alley" says Tatiana Grulois, a PhD candidate at the French aerospace laboratory ONERA, where the prototype was developed, in collaboration with researchers from the French company ULIS, the Institut d'Optique and the French National Center for Scientific Research (CNRS). The new camera has a wide field of view of 130 degrees and very good performance in low light conditions. It is effective over a wide range of infrared light wavelengths (7-14 micrometers), exhibiting great sensitivity to temperature differences.
Οι ερευνητές εκτιμούν ότι ενδεχομένως ο φακός τους να φέρει επανάσταση στον χώρο των υπέρυθρων καμερών ασφαλείας (Thermal Infrared). “Τα τελευταία χρόνια μεγάλες προσπάθειες έχουν καταβληθεί για τη μείωση της τιμής των μη-ψυχόμενων ανιχνευτών IR μεγάλου μήκους κύματος” σημειώνει η Γκρουλουά. “Χάρη στο μικρό πάχος του φακού, η δουλειά αυτή ανοίγει τον δρόμο για φθηνά μη συμβατικά υλικά που δεν χρησιμοποιούνταν 'παραδοσιακά'”.
Hitherto materials such as silicon could not be used in such lenses because a large amount of light was absorbed instead of passing through the material. The French researchers, however, made the lens very thin, turning to a special type of lens, the so-called Fresnel lens, a variation of which is used in lighthouses and cinematographic / theatrical rooms.
Thermal Infrared naftemporiki.gr
