Dispersion limits the transmission distance in optical communications. In simple terms, the broadening of the pulse as it travels along the length of an optical fiber is called dispersion. In fiber-optic measurements, dispersion is often called Chromatic dispersion or short CD. Chromatic Dispersion is variation in the speed of propagation of a light signal with wavelength. Currently installed fiber-optic network spans are limited to around 80 to 100 kilometers that are penalized by dispersion.
ITU-T G.654 fiber has a zero dispersion at about 1300 nm but has lower attenuation at 1550nm. Most importantly, the cut-off is shifted at around 1550nm wavelength region.
Telecommunication grade optical fibers categorized in ITU-T recommendations need to be protected inside the tubes and then wrapped by tapes or yarns before covering with…
A cable design engineer, after reading the customer specification decides the construction details of an optical fiber cable. One of the important considerations he/she needs…
Though there are different solutions to achieve termite resistant, use of Bifenthrin as an active ingredient in the additive is common due to safety factors. Bifenthrin is an insecticide in the pyrethroid family. Pyrethroids are manmade versions of pyrethrins, which come from chrysanthemum flowers. Bifenthrin is used on various agricultural crops and in homes. Bifenthrin was first registered for use by the United States Environmental Protection Agency (U.S. EPA).
Fiber optic cables manufactured in a production unit need to undergo several mechanical tests to ensure their suitability to use in outdoor environment. While some tests are intended to assure the capability to use in outdoor environment, there are some tests that assure their suitability with the installation machines used for deployment. Sheave test is one of such tests. Sheave test is a kind of mechanical test which tests the strength of cable and its sheath to withstand the repeated movements through the sheaves.
Steel tapes are used for corrugation of fiber optic cables to provide extra mechanical strength to the fiber optic cables that is required for some installation conditions. ECCS tape or Electrolytically Chrome Coated Steel tape or Stainless Steel tapes comes in rolls of 1 or 2 kilometers in length. But fiber optic cable lengths during production are usually in lengths of 2, 4 or 6 kilometers.
Fiber optic cables installed near to the high voltage power cables are exposed to effects such as Tracking, Dry brand arcing, Corona effect and Flashover. This article is an attempt to deal with such effects on fiber optic cables. Generally when we talk about the advantageous of fiber optic cables over other metallic media for telecommunications, we say optical fiber cables are free from electro-magnetic influences. That is true as far as the communication signals are concerned.
Most EDFAs provide 20–25 dB amplification over a length of 10 m through a relatively high density of dopants (~500 parts per million). Since such EDFAs compensate for losses accumulated over 80–100 km in a relatively short distance of 10–20 m, they are referred to as the lumped amplifiers. Similar to the case of Raman amplification, fiber losses can also be compensated through distributed amplification. In this approach, the transmission fiber itself is lightly doped (dopant density ~50 parts per billion) to provide the gain distributed over the entire fiber length such that it compensates for fiber losses locally. Such an approach results in a virtually transparent fiber at a specific wavelength when the fiber is pumped using the bidirectional pumping configuration.
Fiber Distribution Point Terminals are points where the Fiber Distribution Point Closure, the associated organizer and optical components are assembled and installed. Distribution cable used…