August 28, 2011
This section discusses various MMF and SMF types currently used for premise, metro, aerial, submarine, and long-haul applications. The International Telecommunication Union (ITU-T), which is a global standardization body for telecommunication systems and vendors, has standardized various fiber types. These include the 50/125-m graded index fiber (G.651), Nondispersion-shifted fiber (G.652), dispersion-shifted fiber (G.653), 1550-nm loss-minimized fiber (G.654), and NZDSF (G.655).
August 28, 2011
FC Connectors
These connectors are used for single-mode and multimode fiber-optic cables. FC connectors offer extremely precise positioning of the fiber-optic cable with respect to the transmitter's optical source emitter and the receiver's optical detector. FC connectors feature a position locatable notch and a threaded receptacle. FC connectors are constructed with a metal housing and are nickel-plated. They have ceramic ferrules and are rated for 500 mating cycles. The insertion loss for matched FC connectors is 0.25 dB. From a design perspective, it is recommended to use a loss margin of 0.5 dB or the vendor recommendation for FC connectors.
August 27, 2011
Extrinsic attenuation can be caused by two external mechanisms: macrobending or microbending. Both cause a reduction of optical power. If a bend is imposed on an optical fiber, strain is placed on the fiber along the region that is bent.
August 27, 2011
Chromatic dispersion is the spreading of a light pulse as it travels down a fiber. Light has a dual nature and can be considered from an electromagnetic wave as well as quantum perspective. This enables us to quantify it as waves as well as quantum particles.
August 27, 2011
Polarization mode dispersion (PMD) is caused by asymmetric distortions to the fiber from a perfect cylindrical geometry. The fiber is not truly a cylindrical waveguide, but it can be best described as an imperfect cylinder with physical dimensions that are not perfectly constant.
August 27, 2011
Polarization dependent loss (PDL) refers to the difference in the maximum and minimum variation in transmission or insertion loss of an optical device over all states of polarization (SOP) and is expressed in decibels.