Single Mode cable is a single stand (most applications use 2 fibers) of glass fiber with a diameter of 8. 3 to 10 microns that has one mode of transmission. Single Mode Fiber with a relatively narrow diameter, through which only one mode will propagate typically 1310 or. Single-mode fiber optic cable (SMF) is a type of optical fiber designed to carry a single ray of light mode directly down the fiber core. Extends data transmission over long distances, from a few meters (MMF) to over 100 kilometers (SMF), depending on module type. 2-core o In optical modules, "core" refers to. Single-mode optical modules use the single-mode fiber, wavelength, connector, and reach specified for the exact PID; OS2 is common in premises cabling, but core, attenuation, dispersion, patching, and link budget must be verified.