{"id":5946,"date":"2018-09-28T01:59:53","date_gmt":"2018-09-28T01:59:53","guid":{"rendered":"https:\/\/vinacap.vn\/?post_type=tin-tuc&p=5946"},"modified":"2023-06-13T08:34:11","modified_gmt":"2023-06-13T08:34:11","slug":"lich-su-hinh-thanh-cap-quang","status":"publish","type":"tin-tuc","link":"https:\/\/vinacap.vn\/en\/archives\/tin-tuc\/lich-su-hinh-thanh-cap-quang","title":{"rendered":"L\u1ecaCH S\u1eec H\u00ccNH TH\u00c0NH C\u00c1P QUANG"},"content":{"rendered":"

N\u0103m 1966, Charles Kuen Kao v\u00e0 George Hockman, hai k\u1ef9 s\u01b0 tr\u1ebb tao ph\u00f2ng th\u00ed nghi\u1ec7m chu\u1ea9n vi\u1ec5n th\u00f4ng (Anh) \u0111\u00e3 c\u00f4ng v\u1ed1 kh\u00e1m ph\u00e1 m\u1edbi \u0111\u1ea7u h\u1ee9a h\u1eb9n v\u1ec1 kh\u1ea3 n\u0103n c\u1ee7a s\u1ee3i quang – nh\u1eefng th\u1ee7y tinh trong su\u1ed1t, linh ho\u1ea1t v\u00e0 m\u1ecfng h\u01a1n m\u1ed9t s\u1ee3i t\u00f3c.<\/p>\n

Khi \u0111\u00f3, vi\u1ec7c s\u1eed d\u1ee5ng s\u1ee3i quang \u0111\u1ec3 truy\u1ec1n th\u00f4ng tin l\u00e0 r\u1ea5t h\u1ea1n ch\u1ebf. M\u1ed9t th\u00f4ng \u0111i\u1ec7p \u0111\u01b0\u1ee3c chuy\u1ec3n th\u00e0nh xung \u00e1nh s\u00e1ng, di chuy\u1ec3n d\u1ecdc theo s\u1ed9 quang \u0111\u1ebfn \u0111i\u1ec3m \u0111\u1ea7u b\u00ean kia. Tuy nhi\u00ean, ch\u00fang ch\u1ec9 c\u00f3 th\u1ec3 \u0111i \u0111\u01b0\u1ee3c m\u1ed9t kh\u1ea3ng c\u00e1ch ng\u1eafn tr\u01b0\u1edbc khi \u00e1nh s\u00e1ng b\u1eaft \u0111\u1ea7u bi\u1ebfn m\u1ea5t. \u0110\u00e2y l\u00e0 hi\u1ec7n t\u01b0\u1ee3ng gi\u1ea3m c\u01b0\u1eddng \u0111\u1ed9 theo t\u1eebng dB\/km (dB \u2013 vi\u1ebft r\u1eaft c\u1ee7a decibel \u2013 l\u00e0 \u0111\u01a1n v\u1ecb \u0111o c\u01b0\u1eddng \u0111\u1ed9 \u00e2m thanh). Charles Kao \u0111\u00e3 quan s\u00e1t nh\u1eefng s\u1ee3i quang c\u00f3 kh\u1ea3 n\u0103ng ch\u1ee9a m\u1ed9t gigaheztz (GHZ) th\u00f4ng tin \u2013 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi 200 k\u00eanh TV hay 200.000 \u0111\u01b0\u1eddng \u0111i\u1ec7n tho\u1ea1i. \u00d4ng th\u1ea5y \u00e1nh s\u00e1ng \u0111\u00e3 tho\u00e1t ra v\u1edbi t\u1ed1c \u0111\u1ed9 1.000 dB\/km, ngh\u0129a l\u00e0 t\u00edn hi\u1ec7u ch\u1ec9 c\u00f2n ch\u01b0a \u0111\u1ebfn m\u1ed9t n\u1eeda d\u00f9 m\u1edbi du chuy\u1ec3n v\u00e0i m\u00e9t.<\/p>\n

\"\"<\/p>\n

Sau nhi\u1ec1u ng\u00e0y nghi\u00ean c\u1ee9u, ti\u1ebfn s\u0129 Kao ph\u00e1t hi\u1ec7n r\u1eb1ng t\u00ecnh tr\u1ea1ng tr\u00ean kh\u00f4ng ph\u1ea3i do b\u1ea3n ch\u1ea5t v\u1ed1n c\u00f3 c\u1ee7a s\u1ee3i th\u1ee7y tinh m\u00e0 b\u1edfi m\u1ed9t v\u00e0i khi\u1ebfm khuy\u1ebft b\u00ean trong v\u1eadt li\u1ec7u. N\u1ebfu lo\u1ea1i b\u1ecf nh\u1eefng v\u1ea5n \u0111\u1ec1 \u0111\u00f3, t\u1ef7 l\u1ec7 th\u1ea5t tho\u00e1t \u00e1nh s\u00e1ng gi\u1ea3m xu\u1ed1ng m\u1ee9c ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c l\u00e0 20 dB\/km. K\u1ebft lu\u1eadn c\u1ee7a Kao nghe c\u00f3 v\u1ebb hoang \u0111\u1eeb\u01a1ng n\u00ean \u00f4ng ch\u1ecbu s\u1ee9c \u00e9p r\u1ea5t l\u1edbn.<\/p>\n

John Midwinter, chuy\u00ean gia v\u1ec1 s\u1ee3i quang t\u1ea1i \u0111\u1ea1i h\u1ecdc LonDon c\u0169ng k\u1ec3 l\u1ea1i: \u201cNhi\u1ec1u ng\u01b0\u1eddi ch\u1ec9 c\u01b0\u1eddi vui v\u1ebb khi t\u00e0i li\u1ec7u \u0111\u01b0\u1ee3c c\u00f4ng b\u1ed1. H\u1ecd ngh\u0129 trong m\u1ed9t ph\u00fat may m\u1eafn n\u00e0o \u0111\u00f3, \u00f4ng \u1ea5y \u0111\u00e3 \u0111\u1ea1t m\u1ee9c 20dB\u201d.<\/p>\n

\"\"<\/p>\n

M\u00e3i 4 n\u0103m sau, n\u0103m 1970 c\u00e1c c\u00f4ng ty vi\u1ec5n th\u00f4ng quy\u1ebft \u0111\u1ecbnh tri\u1ec3n khai v\u00e0 s\u1eed d\u1ee5ng c\u00f4ng ngh\u1ec7 n\u00e0y. M\u1ea1ng c\u00e1p quang b\u1eaft \u0111\u1ea7u ph\u1ed5 bi\u1ebfn \u1edf c\u00e1c th\u00e0nh ph\u1ed1 c\u0169ng nh\u01b0 d\u01b0\u1edbi l\u00f2ng \u0111\u1ea1i d\u01b0\u01a1ng nh\u01b0ng n\u00f3 ch\u1ec9 l\u00e0m n\u00ean c\u00e1ch m\u1ea1ng c\u00e0o nh\u1eefng n\u0103m 90.<\/p>\n

Internet \u0111\u00e3 khi\u1ebfn c\u00f4ng ngh\u1ec7 c\u00e1p quang th\u1ef1c s\u1ef1 b\u00f9ng n\u1ed5. \u201cC\u00e1p quang l\u00e0 c\u01a1 s\u1edf c\u1ee7a Internet v\u00e0 wi fi. Hi\u1ec7n nay, m\u1ecdi doanh nghi\u1ec7p v\u1edbi m\u1ea1ng LAN \u0111\u1ec1u s\u1eed d\u1ee5ng n\u00f3. M\u1ecdi ng\u01b0\u1eddi c\u0169ng nh\u1edd \u0111\u1ebfn c\u00e1p quang m\u1ed7i khi g\u1eedi e-mail, tin nh\u1eafn SMS, \u1ea3nh, video v\u00e0 c\u00e1c file d\u1eef li\u1ec7u kh\u00e1c\u201d, Philip Hargrave, chuy\u00ean gia t\u1ea1i h\u00e3ng cung c\u1ea5p gi\u1ea3i ph\u00e1p truy\u1ec1n th\u00f4ng Nortel, nh\u1eadn x\u00e9t.<\/p>\n

C\u00e1p quang c\u0169ng \u0111ang \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng t\u1ea1i nhi\u1ec1u l\u0129nh v\u1ef1c nh\u01b0 truy\u1ec1n h\u00ecnh m\u1ea1ng IPTV v\u00e0 trong t\u01b0\u01a1ng lai n\u00f3 s\u1ebd l\u00e0 tr\u1ee5 c\u1ed9t c\u1ee7a m\u1ea1ng gi\u1ea3i tr\u00ed gia \u0111\u00ecnh.<\/p>","protected":false},"featured_media":5951,"parent":0,"menu_order":0,"template":"","tags":[],"category-news":[102],"class_list":["post-5946","tin-tuc","type-tin-tuc","status-publish","has-post-thumbnail","hentry","category-news-tin-cong-nghe"],"acf":[],"_links":{"self":[{"href":"https:\/\/vinacap.vn\/en\/wp-json\/wp\/v2\/tin-tuc\/5946","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vinacap.vn\/en\/wp-json\/wp\/v2\/tin-tuc"}],"about":[{"href":"https:\/\/vinacap.vn\/en\/wp-json\/wp\/v2\/types\/tin-tuc"}],"version-history":[{"count":1,"href":"https:\/\/vinacap.vn\/en\/wp-json\/wp\/v2\/tin-tuc\/5946\/revisions"}],"predecessor-version":[{"id":8159,"href":"https:\/\/vinacap.vn\/en\/wp-json\/wp\/v2\/tin-tuc\/5946\/revisions\/8159"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vinacap.vn\/en\/wp-json\/wp\/v2\/media\/5951"}],"wp:attachment":[{"href":"https:\/\/vinacap.vn\/en\/wp-json\/wp\/v2\/media?parent=5946"}],"wp:term":[{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vinacap.vn\/en\/wp-json\/wp\/v2\/tags?post=5946"},{"taxonomy":"category-news","embeddable":true,"href":"https:\/\/vinacap.vn\/en\/wp-json\/wp\/v2\/category-news?post=5946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}