1、 Multimode fiber
The center core of multimode fiber is relatively thick (50 or 62.5 μ m) , can transmit multiple modes of light. Commonly used multimode fiber: 50/125 μ M (European Standard), 62.5/125 μ M (American standard).
In recent years, the application of multimode optical fiber has grown rapidly, mainly because the world’s optical fiber communication technology will gradually turn to in-depth development, and the practicality of parallel optical interconnecting elements will also greatly promote the rapid growth of the short-range multimode optical cable market, thus making the market share of multimode optical fiber continue to rise. With the establishment of Gigabit Ethernet, Ethernet will also be upgraded from Gbps to 10Gbps at a high speed. The 10Gbps Ethernet standard was introduced in the first half of 2002. The continuous progress of communication technology has greatly promoted the development of multimode fiber.
2、 Full-wave optical fiber
With the increasing demand for optical fiber broadband, the communication industry has been trying to find ways to eliminate the “water absorption peak”. In essence, the production and manufacturing technology of full-wave optical fiber is a special production technology that can eliminate the “water absorption peak” of OH ions as much as possible. It can reduce the attenuation peak of ordinary standard single-mode optical fiber near 1383nm to a sufficiently low level. In 1998, Lucent developed a new optical fiber manufacturing technology, which can eliminate OH ions in the optical fiber glass, so that the optical fiber loss is completely controlled by the characteristics of the glass, and the “water absorption peak” is basically “flattened”, so that the optical fiber is at 1280? All wavelengths of 1625 nm can be used for optical communication. Therefore, the difficulties of full-wave optical fiber manufacturing technology have been gradually solved. So far, many manufacturers have been able to produce full-wave optical fiber for communication.
With full-wave fiber, the laser cutting machine can use the coarse wavelength division multiplexing technology, and its channel interval is about 20 nm. At this time, it can still provide a large bandwidth for the network. At the same time, the requirements for the performance of filters and lasers are greatly reduced, which greatly reduces the construction costs of network operators. The emergence of full-wave optical fiber has made a variety of optical communication services more flexible. Because of the wide waveband available for communication, we can divide the waveband of full-wave optical fiber into different communication service segments and use them separately. It can be predicted that in the future, the construction of metropolitan area networks in small and medium-sized cities will use a large number of such full-wave optical fibers.