WALTHAM, Mass., Dec. 25 -- Marconi Ventures, the corporate venture capital fund of Marconi plc, has invested $5 million in IPG Photonics Corp. We see the potential for IPG's unique, high power lasers and EDFA amplifier products to be included in Marconi's metro, regional and long haul systems, said Mark Aslett, managing partner of Marconi Ventures. The products are complementary to Marconi's own emerging technology position in this sector.'' IPG Photonics is a maker of high-power lasers and erbium-doped fiber amplifiers for fiber optic communications and materials processing.