ALPAO recently conducted an interview with Benoit Neichel of Laboratoire d'Astrophysique de Marseilles (LAM) about his experience with adaptive optics and more.
Can you introduce yourself and your organization?
My name is Benoit Neichel, and I have been a researcher at the Laboratoire d’Astrophysique de Marseille (LAM) for about 10 years. Our laboratory is affiliated with the CNRS and Aix Marseille University. My research focuses on instrumentation for large telescopes in astronomy, particularly in the field of Adaptive Optics (AO).
Within the laboratory, there are several scientific groups: one dedicated to galaxy evolution, another focused on exoplanets and objects within the solar system, and finally, the one I work with as the head of research and development in instrumentation. Our goal is to design and develop innovative instrumentation for large ground-based telescopes, including developments in AO.
In what context do you use Adaptive Optics and Deformable Mirrors?
Adaptive Optics in astronomy is used to correct the effects of atmospheric turbulence and restore image quality at the focal plane of large telescopes. These increasingly large telescopes are designed to collect more light to observe objects such as distant galaxies and exoplanets. These telescopes are seen as true photon funnels. A larger telescope also allows for more details in the images; the larger the telescope, the better the discernment of details and the better the understanding of the observed objects. However, this improvement is only possible if the telescope is placed in space, without atmospheric disturbances.
For ground-based telescopes observing through the Earth’s atmosphere, images are degraded and blurred due to atmospheric turbulence. With this disturbance, we won’t see more details with an 8-meter telescope than with a 10 or 20-centimeter telescope.
Thus, without OA, we lose all the capacity of the power of large telescopes; Adaptive Optics allows us to correct the optical aberrations created by atmospheric turbulence, sometimes quite strong. Adaptive Optics systems, such as deformable mirrors and wavefront sensors proposed by ALPAO, will then allow us to measure and correct deformations in real-time to restore image quality.
Currently, our largest telescopes reach 8-10 meters in diameter, but we are investing in the construction of a very large telescope with a diameter of 39 meters, the European Extremely Large Telescope (ELT) in Chile. This telescope will operate exclusively with Adaptive Optics, requiring the most advanced technologies to measure and correct optical aberrations and restore images at the diffraction limit.
What perspectives do you foresee for AO in astronomy?
Regarding Adaptive Optics (AO) in astronomy, we envision several promising perspectives. Firstly, in our constant pursuit of performance enhancement, we seek to push technologies further, particularly by collaborating with industrial partners such as ALPAO. One key aspect of AO performance, exemplified by mirrors, lies in the number of actuators and therefore in the number of correction points. With increasingly large telescopes, such as those reaching forty meters in diameter, we require mirrors with a growing number of actuators to significantly improve image quality. This technological challenge will be necessary from companies like ALPAO.
Secondly, it is crucial for mirrors to react swiftly, as optical aberrations induced by atmospheric turbulence evolve rapidly. To achieve the best performance and image quality possible, we are thus aiming to accelerate the aberration correction process.
And as we always want everything simultaneously, we are working in collaboration with partners like ALPAO to identify critical mirror parameters and improve their design. We are also assessing the impacts of these improvements on astronomical observations to optimize the entire process and make the most of future very large telescopes.
Another essential aspect to mention that drives us towards technology development is the study of exoplanets. Exoplanets are planets orbiting stars much like Earth orbits the Sun, forming planetary systems. This is a major focus of the European Extremely Large Telescope: characterizing exoplanets and their atmospheres and determining if there are other planets with Earth-like characteristics.
Characterizing these exoplanets requires XXL AO systems to correct aberrations and obtain precise images, due to the weakness of the signal to detect. The ultimate goal is to analyze the light from these planets with spectrographs to identify potential biological markers, such as the presence of water, CO2, oxygen, or molecules indicative of life. This quest, as complex as it is fascinating, could provide crucial insights into the processes of life development.
That’s why the technologies offered by ALPAO are indispensable to us: nothing would be possible without AO and deformable mirrors in our telescopes.
Read the rest of the interview here.