Fider optics (Возникновение волоконной оптики) — страница 3

  • Просмотров 7418
  • Скачиваний 571
  • Размер файла 18

волокна, составленного из материала с более высоким индексом преломления чем оболочка. Часть волокно, которое передает свет. Short history of fiber optics. Part 1 Optical communication systems date back two centuries, to the "optical telegraph" that French engineer Claude Chappe invented in the 1790s. His system was a series of semaphores mounted on towers, where human operators relayed messages from one tower to the next. It beat hand-carried messages hands down, but by the mid-19th century was replaced by the electric telegraph, leaving a scattering of "Telegraph Hills" as its most visible legacy. Alexander Graham Bell patented an optical telephone

system, which he called the Photophone, in 1880, but his earlier invention, the telephone, proved far more practical. He dreamed of sending signals through the air, but the atmosphere didn't transmit light as reliably as wires carried electricity. In the decades that followed , light was used for a few special applications, such as signalling between ships, but otherwise optical communications, like the experimental Photophone Bell donated to the Smithsonian Institution, Languished on the shelf. In the intervening years, a new technology slowly took root that would ultimately solve the problem of optical transmission, although it was a long time before it was adapted for communications. It depended on the phenomenon of total internal reflection, which can confine light in a

material surrounded by other materials with lower refractive index, such as glass in air. In 1840s, Swiss physicist Daniel Collodon and French physicist Jacques Babinet showed that light could be guided along jest of water for fountain displays. British physicist John Tyndall popularized light guiding in a demonstration he first used in 1854, guiding light in a jet of water flowing from a tank. By the turn of the century, inventors realized that bent quartz rods could carry light, and patented them as dental illuminators. By the 1940s, many doctors used illuminated plexiglass tongue depressors. Optical fibers went a step further. They are essentially transparent rods of glass or plastic stretched so they are long and flexible. During the 1920s, John Logie Baird in England and

Clarence W. Hansell in the LESSONed States patented the idea of using arrays of hollow pipes or transparent rods to transmit images for television or facsimile systems. However, the first person known to have demonstrated image transmission through a bundle of optical fibers was Heinrich Lamm, than a medical student in Munich. His goal was to look inside inaccessible parts of the body, and in a 1930 paper he reported transmitting the image of a light bulb filament through a short bundle. However, the unclad fibers transmitted images poorly, and the rise of the Nazis forced Lamm, a Jew, to move to America and abandon his dreams of becoming a professor of medicine. Короткая хронология волоконной оптики. Часть 1 Оптические

системы коммуникации датируются два столетия, "оптическим телеграфом", который французский инженер Клод Шапп изобрел в 1790-ых. Его система была рядом семафоров, установленных на башнях, где человеческие операторы передавали сообщения от одной башни до следующего. Это сбивало несшиеся рукой руки сообщений, но к середине 19-ого столетия был заменен электрическим телеграфом, оставляя рассеивание "Холмов Телеграфа" как

его самое видимое наследство. Александр Грэм Белл патентовал оптическую телефонную систему, которую он назвал{вызвал} Фототелефоном, в 1880, но его более раннее изобретение, телефон, оказалось намного более практичным. Он мечтал из посылки сигналов через воздух, но атмосфера не передавала индикатор так надежно, как провода несли электричество. В десятилетия, который следовал, индикатор использовался для нескольких специальных