Optical laboratory
As a physicist professor Väisälä was specialised in optics. Together with his assistants he ground more than a hundred telescope mirrors and lenses in Turku University optical laboratories. The very first construction in Tuorla was a 71-metre long tunnel and an optical laboratory in one of its side-tunnels. Optical work still continues there.
Heat expansion does not hinder manufacturing of optical components in the tunnel for temperature stays at about +10°C. Neither are tremors of the nearby road felt within the base rock.