Tag Archives: supplier

What is the difference between a single mode and multi mode fiber optic connector?

There are 2 major differences one color code. single mode will be white or yellow. multimode will be black or tan. 2nd the hole in the connector ferrel for the fiber. fiber is 125 microns. in a single mode connector the opening is 126 microns. multimode is 127/128.
Single Mode cable is a single strand (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 1550nm. Carries higher bandwidth than multimode fiber, but requires a light source with a narrow spectral width. Synonyms mono-mode optical fiber, single-mode fiber, single-mode optical waveguide, uni-mode fiber.
Single Modem fiber is used in many applications where data is sent at multi-frequency (WDM Wave-Division-Multiplexing) so only one cable is needed – (single-mode on one single fiber)
Single-mode fiber gives you a higher transmission rate and up to 50 times more distance than multimode, but it also costs more. Single-mode fiber has a much smaller core than multimode. The small core and single light-wave virtually eliminate any distortion that could result from overlapping light pulses, providing the least signal attenuation and the highest transmission speeds of any fiber cable type.

Single-mode optical fiber is an optical fiber in which only the lowest order bound mode can propagate at the wavelength of interest typically 1300 to 1320nm.
Multi-Mode cable has a little bit bigger diameter, with a common diameters in the 50-to-100 micron range for the light carry component (in the US the most common size is 62.5um). Most applications in which Multi-mode fiber is used, 2 fibers are used (WDM is not normally used on multi-mode fiber). POF is a newer plastic-based cable which promises performance similar to glass cable on very short runs, but at a lower cost.
Multimode fiber gives you high bandwidth at high speeds (10 to 100MBS – Gigabit to 275m to 2km) over medium distances. Light waves are dispersed into numerous paths, or modes, as they travel through the cable’s core typically 850 or 1300nm. Typical multimode fiber core diameters are 50, 62.5, and 100 micrometers. However, in long cable runs (greater than 3000 feet [914.4 meters), multiple paths of light can cause signal distortion at the receiving end, resulting in an unclear and incomplete data transmission so designers now call for single mode fiber in new applications using Gigabit and beyond.

Multimode& Singlemode fiber are the five types of fiber in common use. Both fibers are 125 microns in outside diameter – a micron is one one-millionth of a meter & 125 microns is 0.005 inches- a bit larger than the typical human hair. Multimode fiber has light travelling in the core in lots of rays, called modes. It’s a bigger core (always 62.5 microns, but sometimes 50 microns) & is used with LED sources at wavelengths of 850 & 1300 nm for slower local area networks (LANs) & lasers at 850 & 1310 nm for networks jogging at gigabits per second or more. Singlemode fiber has a much smaller core, only about 9 microns, so that the light travels in one ray. It is used for telephony & CATV with laser sources at 1300 & 1550 nm. Plastic Optical Fiber (POF) is large core (about 1mm) fiber that can only be used for short, low speed networks.
Step index multimode was the first fiber design but is slow for most makes use of, due to the dispersion caused by the different path lengths of the various modes. Step index fiber is rare – only POF makes use of a step index design today.
Graded index multimode fiber makes use of variations in the composition of the glass in the core to compensate for the different path lengths of the modes. It offers hundreds of times more bandwidth than step index fiber – up to about 2 gigahertz.
Singlemode fiber shrinks the core down so small that the light can only travel in one ray. This increases the bandwidth to infinity – but it is practically limited to about 100,000 gigahertz – that is still a lot!

Multimode& Singlemode fiber are the five types of fiber in common use. Both fibers are 125 microns in outside diameter – a micron is one one-millionth of a meter & 125 microns is 0.005 inches- a bit larger than the typical human hair. Multimode fiber has light travelling in the core in lots of rays, called modes. It’s a bigger core (always 62.5 microns, but sometimes 50 microns) & is used with LED sources at wavelengths of 850 & 1300 nm for slower local area networks (LANs) & lasers at 850 & 1310 nm for networks jogging at gigabits per second or more. Singlemode fiber has a much smaller core, only about 9 microns, so that the light travels in one ray. It is used for telephony & CATV with laser sources at 1300 & 1550 nm. Plastic Optical Fiber (POF) is large core (about 1mm) fiber that can only be used for short, low speed networks.
Step index multimode was the first fiber design but is slow for most makes use of, due to the dispersion caused by the different path lengths of the various modes. Step index fiber is rare – only POF makes use of a step index design today.
Graded index multimode fiber makes use of variations in the composition of the glass in the core to compensate for the different path lengths of the modes. It offers hundreds of times more bandwidth than step index fiber – up to about 2 gigahertz.
Singlemode fiber shrinks the core down so small that the light can only travel in one ray. This increases the bandwidth to infinity – but it is practically limited to about 100,000 gigahertz – that is still a lot!

Source: fiber cable manufacturer