ESO signs contract for next-generation deformable mirror for the VLT

Today, at ESO’s Headquarters in Garching, Germany, ESO and the AdOptica consortium signed a contract for the design and production of a new adaptive mirror, to be installed at our Very Large Telescope (VLT). AdOptica, a consortium made up of two Italian companies, Microgate and A.D.S. International, is a long-standing ESO industrial partner, working on projects such as the adaptive M4 mirror for ESO’s Extremely Large Telescope. ESO’s Director General Xavier Barcons, together with Roberto Biasi of Microgate and Daniele Gallieni of A.D.S. International were present for the signing.

ESO's VLT has four 8-metre Unit Telescopes but at present only one of them, UT4, has an adaptive optics facility, which includes a deformable mirror (the secondary, second in the path of light), as well as four lasers. Using either natural guide stars or artificial guide stars created by these lasers as references, we can measure how much the light from cosmic objects is deformed by Earth’s atmosphere. The adaptive or deformable mirror, which can change its shape very fast and with nanometric precision, then cancels out the deformation of the light in real time, giving us a much sharper view of the cosmos than would otherwise be possible. Because of its adaptive optics systems, together with highly demanded instruments, UT4 is one of the most oversubscribed telescopes on Earth.

Since November 2025, Unit Telescopes 1, 2 and 3 have each been equipped with a laser, as part of the GRAVITY+ upgrade. While these lasers are currently only used for observations with the VLT Interferometer, when all Unit Telescopes are observing together, they can also be used for stand-alone observations (with suitable instruments) — if the telescope they are projected from is equipped with a deformable mirror.

By procuring the production of a new deformable secondary mirror, which is planned for installation on UT3, ESO will expand the adaptive optics capabilities of the VLT with the help of AdOptica, who also built the deformable secondary mirror on UT4. This will reduce the pressure on UT4, since instruments equipped with a wavefront sensor can now also be installed on UT3 and benefit from state-of-the-art adaptive optics corrections. Ultimately, the improvements will allow more observations of cosmic objects in finer detail than is possible today.