News and highlights
The primary mirrors of modern telescope are equipped with an active optics support that not only supports the weight of the mirror but also provides accurate force corrections to maintain the mirror in the optimum shape.
A novel type of electro-pneumatic actuators, originally developed for the INO340 3.4-m telescope, is now offered as a general and cost-convenient solution for all modern active optics telescopes.
The main characteristics are:
- Force range 10 - 1000 N
- Force resolution 0.15 N @ 10 Hz
- Large stroke ±3 mm
- Low dissipation electronics can be integrated in the actuator body
We are developing a state-of-the-art AO system which pairs a high order deformable mirror from ALPAO (with 468 actuators) with a pyramid wavefront sensor (WFS), and a no-noise camera (NUVU 128) for the pupils imaging of the WFS.
The selected design and the no-noise camera allows a very large optimization of the number of corrected modes and magnitude sensitivity.
Thus the system will be able to operate mots efficiently in a variety of conditions: extreme AO in good conditions, classical AO in moderate conditions, and Strehl improvement in bad seeing. Moreover, adding several natural guide star wavefront sensors, a single system could do anything from extreme AO to GLAO, i.e using the same hardware, and adapting the control software parameters to the observation mode. Taking advantage of such a system requires the use of a zoom optics in the imager in order to optimally match the plate scale with the PSF.
On the long term, we think that most mid-size telescopes will have this sort of flexible multi-purpose AO systems as a default.
The DAG telescope having an alt-azimuth mount and Nasmyth foci, its instrument interface will requires either a rotator or a derotator. Although Nasmyth rotators are quite common in state-of-the-art instrument, they imply that the instrument can operate from a rotating flange with a varying gravity vector. A derotator on the light beam avoid this difficulty and allows a significant simplification and greater robustness of the instrument design.
The DAG will therefore have derotators on both Nasmyth foci.
OptoLab.iAi is currently designing and producing both derotator units. These are high-precision mechanisms.
SOLARNET: High-resolution Solar Physics Network
SOLARNET is an EU project aimed at integrating the key European ground-based research infrastructures in the field of high resolution solar physics. SOLARNET will also essntially define and delvelop the instrumentation for the European Solar Telescope (EST) project.
OptoLab.iAi is engaged in a key workpackage which will develop the tools which are needed to characterize the performance of the EST Multi Conjugate Adaptive Optics system, and to generate the information needed to remove the disturbances from observed data which are caused by incomplete compensation of the adaptive optics. In this work package, the distinct competences of several research groups will be combined.
One goal is the development of tools to estimate the long exposure compensated point spread function from telemetry data from the control system throughout the field of view, which is needed to restore spectropolarimetry observations. Another goal is to estimate the statistics for the short exposure compensated point spread function, an information which is used for deconvolution ad speckle imaging.
Secondary and tertiary mirror cells of the European Extremely Larger Telescope (ELT)
In February 2017, following an open tender process ESO has assigned the development contract for the secondary and tertiary mirror cells of the ELT to the Spanish company SENER. OptoLab.iAi contributed as a subcontractor to the successful tender and will then provide various technical analyses and mathematical models during the design phases.
These are complex mechanisms of large size (4-5 m) and extreme accuracy, which support by means of active devices and in all circumstances the surface figure of the mirror with the accuracy of a few nanometers.
Our contribution to this project comprises in particular the integrated (end-to-end) modeling of these mechanisms. This allows to evaluate in a single computation cycle the combined effects of various analyses (static, dynamic, thermal, kinematic) on the optical performance of the mirror. This integrated modeling approach results notably in more efficient design iterations and optimization of all structures and active mechanisms.
One of the latest additions to the international collaborations and consultancy work of OptoLab.iAi is the project of a 3.4-m telescope currently being developed by the Iranian National Observatory.
The INO340 is the project for a new 3.4-m optical and near-infrared Cassegrain telescope embedding active optics.
We are in particular providing assistance to system engineering and to the development of the active optics components.
DAG Telescope (ongoing)
The DAG (Dogu Anadolu Gözlemevi, Eastern Anatolia Observatory) is the project for a new state-of-the-art 4-m optical and near-infrared telescope. This project has now entered the realization phase. The installation of this new telescope is planned on a 3000 m site in eastern Anatolia near the city of Erzurum.
Optolab.iAi has produced during early 2014 the preliminary study for the optical systems of the telescope.
The main contract for the procurement of the telescope has been assigned to the company AMOS (Belgium), with OptoLab.iAi holding the supervisory role in the follow-up and development of the optical aspects of this project.
Furthermore, Prof. Laurent Jolissaint of OptoLab.iAi is also in charge of the development of DAG instruments, including a state-of-the-art adaptive optics and derotators modules.
- Photonic Force Microscope
- Neutron Collimator
- 5 DoF Adaptive Mirror
- Differential Delay Line
Know-how and expertise
Adaptive optics, opto-mechatronic and systems engineering
- Development, design and prototyping of high-precision opto-mechatronics systems, integrating optics, photonics, precision mechanics, electronics and software.
- Inter- and pluridisciplinary applied science and engineering covering in particular the fields of optics, photonics, mechatronics, precision motion, embedded systems, structures, thermal analysis, environmental modeling and impact problems simulation, measurements and tests.
- Pluridisciplinary projects involving a mix of technologies and applied sciences: optomechatronics, computer programming, motion control, fine mechanics, optics, atmospheric phenomena, thermal control.
- Simulation and mathematical modeling of designs, processes and physical phenomena
- Scientific and technical software applications
Prof. Lorenzo Zago
Institut d'Automatisation Industrielle
Haute Ecole d'Ingénierie et de Gestion du Canton de Vaud
Route de Cheseaux 1
Phone: +41 (0)24 557 63 30