Analyse de la chaine de reception optique d'un système lidar du telescope au detecteur

Abstract

The telescope is an optical instrument used to gather the maximum power fordetection in a Lidar system. In this Master thesis we have aligned and characterized a Newtonian telescope developed at CDTA. Furthermore, we studied in detailedexperiments the characterization of the telescope focus, image of a distant target, by using the Brillant-b laser, an IR Pyrocam III camera profiling the optical beam in 2D and 3D displays and various measuring and coupling instruments. We have pointed out optical distortions at and around the focus. They do stem from geometrical origin. This led us to explore solutions specific to certain optical aberrations: spherical aberration, astigmatism andcoma. We have succeeded in reducing them substantially and improving the focusability of the LiDAR optical return signal, thus enabled to be fully coupled into a sensitive and fast detector. In addition to that, we show that it is possible to enhance the coupling efficiency by the use of microlenses as an coupling optical device.