by Acad. Yevgeny DIANOV, Director of the Fiber Optics Scientific Center, RAS (Moscow)
History of human civilization is also history of development of communication means. Advances in science and technology were accompanied by emergence of new information transmission methods. Suffice it to mention the invention of wire telegraph and telephone in the 19th century. But the 20th century was characterized by distribution of radio communications including satellite one. Wavelength reduction of carrier radio radiation (frequency increase) allowed transmission of more and more data volumes. But even these opportunities could not keep up with the growing requirements of society. Specialists became aware of the necessity to find a new method of communication, i.e. using optical radiation, which promised growth of information transmission rate more than 10,000 times, if compared with radio communication. The current scales of using optical communication via fiber lightguide confirmed the expectations. However this material information carrier also has its limitations. What is to be done? Let us clear it up.
Spectrum of optical losses of fiber lightguides. O, E, S, C, L, U are designations of spectral bands used in literature. EDFA is an amplification band of erbium fiber amplifier. ALLWave and SSMF are types of fiber lightguides.
All continents of our planet are connected at present by under-water fiber-optic lines. By 2010 the total extent of laid fiber lightguides including transatlantic and transpacific under-water systems reached 1 bln km. In developed countries such light-guide is now connected to each house thus providing access to wide-band information through Internet. According to the estimates the number of the global network users will reach 5 bln in 2015. By the way, this very network emerged due to the development of the fiber-optic communication.
The outstanding results in creation of the said systems were achiev ... Читать далее