CHARLTON, Mass., Aug. 21 -- FiberCore Inc. has received $39 million in new orders from existing South American customers. FiberCore will fill the orders for its single mode optical fiber starting this year and continue production throughout 2002 from its recently acquired facility, Xtal Inc., located in Brazil.In addition to its standard multimode and single-mode fiber, the company recently introduced a new fiber system, GigaGrade Pick and Place. The new system enhances the usefulness of multimode fiber by providing long link lengths at gigabit speeds -- promising high bandwidths when used with LEDs, the company said.