title: Reduction of material mass of optical component in cryogenic camera by using high-order Fresnel lens on a thin germanium substrate.
abstract: We designed a compact infrared cryogenic camera using only one lens mounted inside the detector area. In the field of cooled infrared imaging systems, the maximal detector area is determined by the dewar. It is generally a sealed and cooled environment dedicated to the infrared quantum detector. By integrating an optical function inside it, we improve the compactness of the camera as well as its performances. The originality of our approach is to use a thin integrated optics which is a high quality Fresnel lens on a thin germanium substrate. The aim is to reduce the additional mass of the optical part integrated inside the dewar to obtain almost the same cool down time as a conventional dewar with no imaging function. A prototype has been made and its characterization has been carried out.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Grulois
authors.forename: Guillaume
authors.initials: G
authors.lastname: Druart
authors.forename: Hervé
authors.initials: H
authors.lastname: Sauer
authors.forename: Mathieu
authors.initials: M
authors.lastname: Chambon
authors.forename: Nicolas
authors.initials: N
authors.lastname: Guérineau
authors.forename: Serge
authors.initials: S
authors.lastname: Magli
authors.forename: Gillles
authors.initials: G
authors.lastname: Lasfargues
authors.forename: Pierre
authors.initials: P
authors.lastname: Chavel