Improving telescope vision with artificial guide stars

Designed and built by ESO - the Very Large Telescope (VLT) and Extremely Large Telescope (ELT) are some of the world's most advanced optical telescopes that form the flagship facility for European ground-based astronomy. These huge telescopes require an adaptive optics system to eliminate wavefront errors resulting from atmospheric aberrations. TNO is a leading supplier, to ESO, of laser projection systems that create artificial guide stars at the edge of earth’s atmosphere to act as a beacon for a wavefront sensor to measure the optical distortion created by the atmosphere, so that it can be compensated by a deformable mirror.

Martijn Brouwer, Optical Specialist at TNO, commented: “Aiming the light from our Laser Launch System, which forms the artificial guide stars, required the development of very high precision mirrors. Though we had no prior experience of Optical Surfaces Ltd. their website showed several compelling telescope optics case studies that gave us the confidence to work with them. We have not been disappointed by the excellent surface accuracy (ʎ / 20) and quality (20/10) they have routinely delivered. Additionally, we purchased a reference flat with a diameter of 400mm, which we use for characterisation of the wavefront error of the laser guide stars.”

He added: “From a customer perspective the price/performance ratio of all the telescope optics supplied by Optical Surfaces has impressed us. The people at Optical Surfaces do a very thorough job. We particularly appreciate the knowledgeable support they have provided throughout our successful product development process.”