In general, single-mode fiber and multimode fiber cannot be directly connected. A direct connection can lead to severe signal loss and unstable communication, with the intuitive result that the transmission. But what happens when you need to connect an existing multi-mode campus network to a new single-mode service provider link? You can't just splice them together. It depends on your system setup. This increases the risk of. Multimode fiber cabling is used for indoor, short distance applications and single-mode fiber cabling is used for outdoor, long distance application. To connect multimode to single-mode and single-mode to multimode, a fiber-to-fiber media converter is needed to convert multimode to single-mode. Fiber optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information.