Fiber Optic Communications in Japan

Latest technology and application field of fiber optic communications systems in Japan are introduced. Very low loss fibers made by the vapour phase axial deposition (VAD) method, mode stabilized laser diodes (LD) for single mode fibers (SMF) and wavelength division multiplexing (WDM) filters are latest topics of optical devices. Inter-office trunk systems by using graded index (GI) multi-mode fibers (MMF) have been comercially utilized. Long-haul transmission systems by using step index (ST) single-mode fibers (SMF) are being developed now. Optical subscriber systems and submarine systems will be developed soon. Various optical technologies are still advancing very rapidly.