fiber optic

inglemode fiber is an optical fiber that is constructed to carry only a single ray of light. The light travels only with one wavelength trought the core and therefore singlemode prevent light rays overlapping. As a result destroying of data is not given, but can be appear at multimode fiber. With singlemode you can reach longer distances in opposite to multimode fiber. The distance of singlemode can be 50 times higher as multimode fiber. Another advantage is in some cases the higher bandwidth of singlemode fiber. Single-mode fibers are used in long-distance cables, but they require connectors with better precision and expensive devices. On this kind of fiber the light has only one way of travelling inside the fiber core. The core diameter is between 7 and 10 microns and its cladding diameter is around 125 microns, so both multi-mode and mono-mode cables have the same diameter, what makes the difference is the diameter of the core. There are three types of single-mode fibers: non dispersion-shifted fiber (NDSF), dispersion-shifted fiber (DSF) and non zero-dispersion-shifted fibers (NZ-DSF).

ultimode fiber is an optical fiber that is constructed to carry multiple light rays or modes concurrently. Each at a marginally different reflection angle within the optical fiber core. Mulitmode fiber transmission is used for relatively short distances tend to disperse over longer length(modal dispersion). On multimode fibers the core diameter is greater than the core diameter of single-mode fibers, making the light to have several propagation modes, i.e. the light goes through the fiber core using several paths and not using a single path, like in single-mode fibers. Multimode fibers have a core diameter 50 to 100 microns (typical commercial values are 50, 62.5 and 100 microns) and a cladding diameter of 125 microns. Multimode fibers can be classified into graded-index and step-index, depeding on the refraction index between the core and the cladding – on graded-index there is a gradual change between the core and the cladding, while on step-index this change is abrupt. Step-index fibers can transmit data up to 50 Mbps, while grade-index fibers can transmit data up to 1 Gbps. Multi-Mode fibers are also known as MMF and they are used by short-distance fibers.