Technology, optical amplification technology, including erbium-doped fiber amplifier (EDFA), distributed Raman fiber amplifier (DRFA), semiconductor amplifier (SOA) and optical time division multiplexing (OTDM) technology development and wide application of optical communication technology continues toward higher speed, greater capacity communication systems development, and advanced optical manufacturing technology not only stable, reliable and adequate margin of transmission, optical communication can meet the demand for large bandwidth and reduce the non-linear damage.
Multimode fiber Multimode fiber center core is coarse (50 or 62.5 m), to be available for a variety of modes of light. Commonly used multimode fiber: 50/125 m (European standard), 62.5/125 m (U.S. standard).
Recent years the application of multi-mode fiber growth rapidly, primarily because of optical communication technology world is going towards in-depth development of parallel optical interconnect devices practical and greatly promote the short-range multi-mode fiber optic cable market to grow rapidly, thereby so that the market share of multi-mode optical fiber continued to rise. With the establishment of Gigabit Ethernet, Gbps Ethernet will be from the high rate of upgrade to 10Gbps, 10Gbps Ethernet standard (IEEE802.3ae), was introduced in the first half of 2002. Communication technology continues to progress, greatly promoted the development of multi-mode optical fiber.
Full-wave fiber-optic As people continued expansion of fiber optic bandwidth, communications industry has been trying to explore the elimination of "water absorption" approach. Full-wave fiber (All-WaveFiber) to the production technology, in essence, that means as far as possible eliminate the OH ions through the "water absorption" of a specific production technology, which enables ordinary standard single-mode fiber in the 1383nm attenuation peak near the office, down to low enough levels. In 1998, the United States, Lucent developed a new optical fiber manufacturing technology, it can eliminate the OH ions in the glass fiber so that fiber loss is entirely controlled by the characteristics of glass, "water absorption" basically "flattened" a, so that optical fiber in 1280? 1625nm wavelength range of all can be used for optical communication, thus, full-wave optical fiber manufacturing technology problems have gradually been resolved. So far, many manufacturers have been able to produce full-wave fiber-optic communications, such as Lucent All-wave optical fiber, Corning SMF-28e fiber, Alcatel ESMF Enhanced single-mode fiber, and fiber Fujikura's LWPfiber and so on.
2000 4 months, fiber optic products to meet the latest technologies, ITU G.652 single-mode optical fiber standards on a large scale amendment to the official final version in October, corresponding to the IEC (International Electrotechnical Commission) classification number B1.3, ITU-T will be "full-wave fiber" is defined as G.652c class fiber, mainly used in the G.957 ITU-T requirements and G.691 SDH transmission systems with optical amplification provided for single-channel SDH transmission systems and up to STM-64 (10Gb / s) of the ITU-T G.692 with optical amplification of WDM transmission systems, the 1550nm wavelength region generally need high-speed transmission wavelength dispersion regulator.
Full-wave fiber in the metro construction will be much to accomplish. From the network operator point of view, with full-wave fiber, you can use coarse wavelength division multiplexing technology, whichever is the channel spacing is about 20nm, then the network can provide greater bandwidth, while at the same time, performance requirements on the filter and the laser are greatly reduced, which greatly reduces the capital cost of network operators. The emergence of full-wave fiber optical communications business with a variety of more flexibility, because a wide band for communication purposes, we can be full-wave optical fiber communication band is divided into different business segment, respectively, use. The foreseeable future the construction of MAN medium and small cities, will be a lot of use this full-wave fiber.
Human pursuit of high-speed, broadband communications network is a never-ending desire, in the current exponential growth in bandwidth demand situation, the full-wave fiber-optic industry is more and more concerned about the many advantages of its communications industry has been widely accepted.
Polymer optical fiber Present communication backbone has been realized as the matrix of quartz optical fiber communications, however, access and Fiber-home (FTTH) project, the silica fiber has encountered greater difficulties. As the quartz fiber core is very small (6? 10 m), fiber coupling and then face each other technical difficulties, because the need for high-precision alignment technology, the short distance, the contact number of the access network the user is a problem. The polymer optical fiber (polymeropticalfiber, POF) due to its large core diameter (0.2? 1.5mm), so you can use the cheap and simple plastic connectors, and its toughness and flexibility are good, large numerical aperture, you can use cheap laser source, in the visible region have low loss window for access network. Polymer optical fiber FTTH project is the most promising transmission medium.
Polymer optical fiber is divided into multi-mode step-type SI-POF and multimode graded two major categories of GI-POF, as SIPOF serious mode dispersion, bandwidth and twisted pair copper wire similar restrictions within the 5MHz, Even in a very short distance of communication can not satisfy the FDDI, SDH, B-ISDN communication standards, and GIPOF fiber core of refractive index distribution is parabolic, it greatly reduces the modal dispersion of the signal transmission bandwidth can reach 2.5 within the 100m Gbps or more, in recent years, GIPOF POF research has been the main direction. Recently, N. Tanio predicted theoretically amorphous perfluorinated vinyl ether Polybutene theoretical loss at 1300nm Department limit 0.3dB/km, Department of loss in the 500nm can be as low as 0.15dB/km, it can and comparable to the loss of silica fiber. G. Giorgio and others reported that perfluoro GIPOF 100m data transfer rate reached 11Gbps. Therefore, GIPOF may become the access network, user network so the ideal transmission medium.
Photonic crystal fiber Photonic crystal fiber (photoniccrystalfiber, PCF) and others by ST.J.Russell made in 1992. On the quartz fiber is, PCF in which the structural features are arranged between the air holes evenly along the axis, so that looking from the fiber end, there is a two-dimensional periodic structure, if one hole destruction and loss, will be the defect, use of this flaw, in which light can spread. PCF with different single mode optical fiber, as it is ordered by the periodic air holes form a single crystal material, so there are hollow optical fiber (holeyfiber) or micro fiber (micro-structuredfiber) called. PCF has a special dispersion and nonlinearity in optical communications will have wide application.