IPG Photonics Corporation, designer and manufacturer of high-performance fiber lasers and amplifiers, has opened its new world headquarters and manufacturing facilities in Oxford, Mass. The new facilities will serve as IPG's base for engineering, high-volume manufacturing and component testing for North and South American customers.   . . .    Doug Doty joined the CEO senior management team at Cutting Edge Optronics Inc. Doty will play a lead role in quality-related activities including ISO 9001 certification and Six Sigma programs.