Physical specification for single mode fiber and multimode fiberOptical fibers are divided into multimode and singlemode fibers according to the mode field. Multimode is divided into 62.5/125μm, 50/125μm and 100/140μm. Commonly used are 62.5/125μm and 50/125μm multimode fiber;Single-mode fiber requires only one specification, that is, 9/125μm single-mode fiber.