GSI Group Inc. of Assumption, Ill., has purchased a beryllium mirrors and structures business from Thales Optronics Ltd. of Glasgow, UK, for an undisclosed amount. The technology of the acquired company, which includes advanced scanning mirrors, is expected to strengthen GSI’s optical scanning and precision optics product lines. The combined technologies are used in a variety of applications in the electronics, aerospace and telecommunications industries. Teams from both companies have collaborated for several years.