Modes and Classifications

􀂙Mode
􀁽 the propagation characteristics of an
electromagnetic wave as it travels through a type
of fiber
The number of propagation modes of a fiber is
related to the core diameter, index of refraction and
wavelength of light
􀂙Two basic modes of transmission
􀁽 Single Mode
􀁽 Multimode

Single Mode Step-Index Fiber

Small core diameter
􀂙index of refraction for core is smaller than
multimode
􀂙only one mode of propagation
􀁽 all light rays travel the same path
􀂙light source is Injection Laser Diode(ILD)
􀂙Long distance, high speed transmission