Optical Technology

One of the most interesting developments in telecommunication is the rapid progress of optical communication where optical fibers are replacing conventional telephone wires and cables. Just as digital technologies greatly improved the telephone system, optical communication promises a considerable increase in capacity, quality, performance and reliability of the global telecommunication network. New technologies such as optical fibers will increase the speed of telecommunication and provide new, specialized information service. Voice, computer data, even video images, will be increasingly integrated into a single digital communication network capable to process and transmit virtually any kind of information.

It is a result of combining two technologies: the laser, first demonstrated in 1960, and the fabrication 10 years later of ultra-thin silicon fibers which can serve as lightwave conductors. With the further development of very efficient lasers plus continually improved techniques to produce thin silica fibers of incredible transparency, optical systems can transmit pulses of light as far as 135 kilometers without the need for amplification or regeneration.

At present high-capacity optical transmission systems are being installed between many major US cities at a rapid rate. The system most widely used now operates at 147 megabits (thousand bits) per second and accommodates 6,000 circuits over a single pair of glass fibres (one for each direction of transmission). This system will soon be improved to operate at 1.7 gigabits (thousand million bits) per second and handle 24,000 telephone channels simultaneously.

A revolution in information storage is underway with optical disk technology. The first optical disks appeared in the early 1970-s. They were and are used to record videofilms, but in a continuous spiral rather than digitally.

The first digital optical disks were produced in 1982 as compact disks for music. They were further developed as a storage medium for computers. The disks are made of plastics coated with aluminium. The information is recorded by using a powerful laser to imprint bubbles on the surface of the disk. A less powerful laser reads back the pictures, sound or information. An optical disk is almost indestructible and can store about 1000 times more information than a plastic disk of the same size.

The latest optical disk development is a system which enables computer users to record their own information on a glass or plastic disk coated with a thin film of tellurium. Such a disk can store 200 megabytes (200 million characters).

Besides, it is reported that an optical equivalent of a transistor has been produced and intensive research on optical electronic computers is underway at a number of US corrinies as well as in countries around the world.

Деловая часть sightseeing

Those who go abroad either for pleasure or on business are always faced with a dilemma of how to make the best use of their time. It is particularly difficult for a businessman for whom business should come before pleasure as the English saying goes. So before going on a trip you should read up on the country you are going to and think of places of interest to be visited. A lot depends on your taste, of course. You may, for instance, be keen on art galleries and museums or prefer to visit exhibitions and displays.

For their part the receiving party also tries to make their guests' stay pleasant and entertaining. Very often they arrange an interesting cultural programme that will give the visitors an idea of the countries present and past, its history, customs and traditions.

Every third world country has something to be particularly proud of. Ancient temples, monu­ments, architectural masterpieces and other attractions make a list of sights not to be missed by visitors. In India these will include Agra's Taj Mahal, in Iraq visitors are sure to be taken to Babylon, in Egypt to the famous pyramids.

The economic and social successes of developing countries are very impressive, too. They give a clue to a better understanding of peopled way of thinking and life style and that in turn contributes to the further development of advantageous cooperation.