CORNING, N.Y. -- In a move that should improve splicing efficiency and lower system installation costs, Corning Incorporated has tweaked its production process for single-mode fiber and tightened its core/clad concentricity specs by 25 percent. Corning will tighten fiber optic specifications to meet customer demand. According to Corning, the move was made in response to customer demand for improvements in spliceability. "Fiber geometry, such as tighter core/clad concentricity, contributes to smoother, trouble-free splicing," said Curt Weinstein, Corning's telephony marketing manager. That, he added, cuts labor and associated costs for system installers. Corning, which uses the outside vapor deposition process, said that it had to "reinvent several of its manufacturing processes" to produce the tighter specs. Corning told Photonics Spectra that the manufacturing changes took place in the "lay-down" phase where a vapor of silica and germanium "soot" is deposited on the outside of the preform. The key was techniques for controlling concentricity in the lay-down phase.