An innovative adaptive optics system using only one sensor
Resolution in an optical system can be affected by various parameters: on the one hand, all the optical defects and aberrations generated by the system itself, and, on the other hand, all those coming from the medium of light propagation. A classic adaptive optics system has 5 main elements: an adaptive mirror, a command, a beamsplitter, a main imager, a wafront sensor with its camera. The main limitations associated with this configuration are as follows:
• Two specific sensors are necessary, which implies a significant bulk
• Having two sensors and two optical paths also involves differential mechanical stresses that can induce optical aberrations
• The beamsplitter, which is essential for taking the light output that is necessary for the wavefront analysis assembly, reduces the flux for the main sensor. This is an important limitation for the detectivity of the system.
The solution is an innovative adaptive optics system using only one sensor. In addition to being the main sensor for high resolution and/or sensitivity, it will also be the sensor for the analysis of the wavefront in order to control the deformable mirror in real time.
A prototype has been developed and tested at ENS Paris (Physics Laboratory), and at the Pic du Midi Observatory (France) during several technical missions.