{"id":4007,"date":"2025-09-15T11:12:00","date_gmt":"2025-09-15T11:12:00","guid":{"rendered":"https:\/\/lp.szlogic.cn\/glossary\/polarization-mode-dispersion-in-fiber-optics\/"},"modified":"2026-06-10T01:16:59","modified_gmt":"2026-06-10T01:16:59","slug":"polarization-mode-dispersion-in-fiber-optics","status":"publish","type":"post","link":"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/polarization-mode-dispersion-in-fiber-optics","title":{"rendered":"PMD (Ph\u00e2n t\u00e1n ch\u1ebf \u0111\u1ed9 ph\u00e2n c\u1ef1c) l\u00e0 g\u00ec trong k\u1ef9 thu\u1eadt s\u1ee3i quang"},"content":{"rendered":"<figure class=\"wp-block-image aligncenter size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1200\" height=\"712\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1d055290fe85422eb9f0a2076fa31562.webp\" alt=\"What is polarization mode dispersion in fiber optics today\" class=\"wp-image-4005\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1d055290fe85422eb9f0a2076fa31562.webp 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1d055290fe85422eb9f0a2076fa31562-300x178.webp 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1d055290fe85422eb9f0a2076fa31562-1024x608.webp 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1d055290fe85422eb9f0a2076fa31562-768x456.webp 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/1d055290fe85422eb9f0a2076fa31562-18x12.webp 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Trong h\u00e0nh tr\u00ecnh kh\u00f4ng ng\u1eebng ngh\u1ec9 nh\u1eb1m \u0111\u1ea1t \u0111\u01b0\u1ee3c t\u1ed1c \u0111\u1ed9 d\u1eef li\u1ec7u cao h\u01a1n\u2014t\u1eeb 100G v\u00e0 400G \u0111\u1ebfn 800G \u0111ang n\u1ed5i l\u00ean\u2014c\u00e1c k\u1ef9 s\u01b0 m\u1ea1ng \u0111\u1ed1i m\u1eb7t v\u1edbi v\u00f4 s\u1ed1 th\u00e1ch th\u1ee9c. M\u1eb7c d\u00f9 suy hao v\u00e0 ph\u00e2n t\u00e1n s\u1eafc th\u00e1i \u0111\u00e3 \u0111\u01b0\u1ee3c bi\u1ebft r\u00f5 v\u00e0 d\u1ec5 ki\u1ec3m so\u00e1t, m\u1ed9t hi\u1ec7u \u1ee9ng tinh vi v\u00e0 nguy hi\u1ec3m h\u01a1n l\u1ea1i \u1ea9n n\u00e1u b\u00ean trong c\u00e1p s\u1ee3i quang: <strong>PMD (Ph\u00e2n t\u00e1n ch\u1ebf \u0111\u1ed9 ph\u00e2n c\u1ef1c)<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">H\u01b0\u1edbng d\u1eabn n\u00e0y s\u1ebd l\u00e0m r\u00f5 kh\u00e1i ni\u1ec7m PMD, gi\u1ea3i th\u00edch l\u00fd do v\u00ec sao n\u00f3 l\u00e0 y\u1ebfu t\u1ed1 then ch\u1ed1t trong c\u00e1c m\u1ea1ng quang hi\u1ec7n \u0111\u1ea1i, \u0111\u1ed3ng th\u1eddi tr\u00ecnh b\u00e0y c\u00e1ch gi\u1ea3m thi\u1ec3u \u1ea3nh h\u01b0\u1edfng c\u1ee7a n\u00f3 \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o hi\u1ec7u su\u1ea5t ho\u00e0n h\u1ea3o.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" ><strong>\u27a4 \u0110i\u1ec3m n\u1ed5i b\u1eadt<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p><strong>Ph\u00e2n t\u00e1n ch\u1ebf \u0111\u1ed9 ph\u00e2n c\u1ef1c<\/strong> x\u1ea3y ra khi \u00e1nh s\u00e1ng di chuy\u1ec3n v\u1edbi c\u00e1c t\u1ed1c \u0111\u1ed9 kh\u00e1c nhau trong s\u1ee3i quang. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 l\u00e0m t\u00edn hi\u1ec7u tr\u1edf n\u00ean m\u1edd nh\u00f2e v\u00e0 g\u00e2y ra l\u1ed7i trong d\u1eef li\u1ec7u.<\/p><\/li><li><p>Vi\u1ec7c s\u1eed d\u1ee5ng c\u00e1c s\u1ee3i quang duy tr\u00ec ph\u00e2n c\u1ef1c c\u00f3 th\u1ec3 gi\u1ea3m \u0111\u00e1ng k\u1ec3 PMD. \u0110i\u1ec1u n\u00e0y gi\u00fap gi\u1eef cho t\u00edn hi\u1ec7u m\u1ea1nh m\u1ebd v\u00e0 d\u1ec5 hi\u1ec3u.<\/p><\/li><li><p>Ki\u1ec3m tra PMD th\u01b0\u1eddng xuy\u00ean th\u00f4ng qua vi\u1ec7c th\u1eed nghi\u1ec7m s\u1ee3i quang l\u00e0 r\u1ea5t quan tr\u1ecdng. N\u00f3 gi\u00fap \u0111\u1ea3m b\u1ea3o m\u1ea1ng ho\u1ea1t \u0111\u1ed9ng \u1ed5n \u0111\u1ecbnh v\u00e0 ng\u0103n ng\u1eeba m\u1ea5t d\u1eef li\u1ec7u.<\/p><\/li><li><p>C\u00e1c y\u1ebfu t\u1ed1 nh\u01b0 h\u00ecnh d\u1ea1ng s\u1ee3i, \u1ee9ng su\u1ea5t, bi\u1ebfn \u0111\u1ed5i nhi\u1ec7t \u0111\u1ed9 v\u00e0 l\u00e3o h\u00f3a c\u00f3 th\u1ec3 l\u00e0m tr\u1ea7m tr\u1ecdng th\u00eam PMD. V\u00ec v\u1eady, c\u1ea7n theo d\u00f5i s\u00e1t c\u00e1c y\u1ebfu t\u1ed1 n\u00e0y.<\/p><\/li><li><p>Vi\u1ec7c \u00e1p d\u1ee5ng thi\u1ebft k\u1ebf s\u1ee3i quang ch\u1ea5t l\u01b0\u1ee3ng cao c\u00f9ng c\u00e1c gi\u1ea3i ph\u00e1p \u0111\u1eb7c bi\u1ec7t c\u00f3 th\u1ec3 gi\u00fap ki\u1ec3m so\u00e1t PMD. \u0110i\u1ec1u n\u00e0y gi\u00fap d\u1eef li\u1ec7u truy\u1ec1n nhanh h\u01a1n v\u00e0 \u0111\u00e1ng tin c\u1eady h\u01a1n.<\/p><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" ><strong>\u27a4 PMD (Ph\u00e2n t\u00e1n ch\u1ebf \u0111\u1ed9 ph\u00e2n c\u1ef1c) th\u1ef1c ch\u1ea5t l\u00e0 g\u00ec?<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">T\u00edn hi\u1ec7u \u00e1nh s\u00e1ng truy\u1ec1n qua s\u1ee3i quang bao g\u1ed3m m\u1ed9t s\u00f3ng \u0111i\u1ec7n t\u1eeb c\u00f3 tr\u1ea1ng th\u00e1i <strong>ph\u00e2n c\u1ef1c<\/strong> nh\u1ea5t \u0111\u1ecbnh\u2014n\u00f3i c\u00e1ch kh\u00e1c, l\u00e0 h\u01b0\u1edbng dao \u0111\u1ed9ng c\u1ee7a s\u00f3ng \u0111\u00f3.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong m\u1ed9t s\u1ee3i quang l\u00fd t\u01b0\u1edfng, ho\u00e0n to\u00e0n tr\u00f2n, \u00e1nh s\u00e1ng c\u00f3 c\u00e1c tr\u1ea1ng th\u00e1i ph\u00e2n c\u1ef1c kh\u00e1c nhau s\u1ebd di chuy\u1ec3n v\u1edbi c\u00f9ng m\u1ed9t t\u1ed1c \u0111\u1ed9. Tuy nhi\u00ean, tr\u00ean th\u1ef1c t\u1ebf, s\u1ee3i quang kh\u00f4ng ho\u00e0n h\u1ea3o. Ch\u00fang t\u1ed3n t\u1ea1i nh\u1eefng b\u1ea5t \u0111\u1ed1i x\u1ee9ng vi m\u00f4, \u0111\u1ed9 cong v\u00e0 \u1ee9ng su\u1ea5t. Nh\u1eefng khi\u1ebfm khuy\u1ebft n\u00e0y khi\u1ebfn s\u1ee3i quang tr\u1edf th\u00e0nh <strong>l\u01b0\u1ee1ng chi\u1ebft<\/strong>, ngh\u0129a l\u00e0 \u00e1nh s\u00e1ng truy\u1ec1n theo m\u1ed9t tr\u1ea1ng th\u00e1i ph\u00e2n c\u1ef1c (ho\u1eb7c ch\u1ebf \u0111\u1ed9) s\u1ebd di chuy\u1ec3n h\u01a1i nhanh h\u01a1n so v\u1edbi tr\u1ea1ng th\u00e1i c\u00f2n l\u1ea1i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PMD l\u00e0 \u0111\u1ed9 tr\u1ec5 ch\u00eanh l\u1ec7ch gi\u1eefa hai ch\u1ebf \u0111\u1ed9 ph\u00e2n c\u1ef1c n\u00e0y.<\/strong> \u0110\u1ed9 tr\u1ec5 n\u00e0y khi\u1ebfn c\u00e1c xung \u00e1nh s\u00e1ng lan r\u1ed9ng khi truy\u1ec1n \u0111i tr\u00ean kho\u1ea3ng c\u00e1ch, c\u00f3 th\u1ec3 ch\u1ed3ng l\u1ea5n l\u00ean c\u00e1c xung li\u1ec1n k\u1ec1. Hi\u1ec7n t\u01b0\u1ee3ng nhi\u1ec5u gi\u1eefa c\u00e1c k\u00fd hi\u1ec7u (ISI) n\u00e0y d\u1eabn \u0111\u1ebfn l\u1ed7i v\u00e0 cu\u1ed1i c\u00f9ng l\u00e0 s\u1ef1 c\u1ed1 ho\u00e0n to\u00e0n c\u1ee7a li\u00ean k\u1ebft.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" ><strong>\u27a4 T\u1ea1i sao PMD l\u00e0 v\u1ea5n \u0111\u1ec1 nghi\u00eam tr\u1ecdng \u0111\u1ed1i v\u1edbi c\u00e1c m\u1ea1ng hi\u1ec7n \u0111\u1ea1i?<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img decoding=\"async\" width=\"1200\" height=\"712\" src=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/8b0115c22acc4ab0bfbe8cc64f0ab828.webp\" alt=\"Polarization Mode Dispersion\" class=\"wp-image-4006\" srcset=\"https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/8b0115c22acc4ab0bfbe8cc64f0ab828.webp 1200w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/8b0115c22acc4ab0bfbe8cc64f0ab828-300x178.webp 300w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/8b0115c22acc4ab0bfbe8cc64f0ab828-1024x608.webp 1024w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/8b0115c22acc4ab0bfbe8cc64f0ab828-768x456.webp 768w, https:\/\/resourceslp.szlogic.cn\/wp-content\/uploads\/2026\/05\/8b0115c22acc4ab0bfbe8cc64f0ab828-18x12.webp 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u1ea2nh h\u01b0\u1edfng c\u1ee7a PMD l\u00e0 kh\u00f4ng \u0111\u00e1ng k\u1ec3 trong c\u00e1c h\u1ec7 th\u1ed1ng c\u0169, t\u1ed1c \u0111\u1ed9 d\u1eef li\u1ec7u th\u1ea5p. Tuy nhi\u00ean, n\u00f3 \u0111\u00e3 tr\u1edf th\u00e0nh m\u1ed9t r\u00e0ng bu\u1ed9c thi\u1ebft k\u1ebf ch\u00ednh v\u00ec nhi\u1ec1u l\u00fd do sau:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p style=\"margin: 0px;\"><strong>T\u1ed1c \u0111\u1ed9 d\u1eef li\u1ec7u cao h\u01a1n:<\/strong> Khi t\u1ed1c \u0111\u1ed9 bit t\u0103ng l\u00ean (v\u00ed d\u1ee5: t\u1eeb 10G l\u00ean 400G), kho\u1ea3ng th\u1eddi gian gi\u1eefa c\u00e1c xung (chu k\u1ef3 bit) gi\u1ea3m \u0111i. M\u1ed9t \u0111\u1ed9 tr\u1ec5 PMD c\u1ed1 \u0111\u1ecbnh chi\u1ebfm t\u1ef7 l\u1ec7 l\u1edbn h\u01a1n trong chu k\u1ef3 bit n\u00e0y, l\u00e0m t\u0103ng m\u1ea1nh kh\u1ea3 n\u0103ng x\u1ea3y ra l\u1ed7i.<\/p><\/li><li><p style=\"margin: 0px;\"><strong>Truy\u1ec1n d\u1eabn \u0111\u01b0\u1eddng d\u00e0i:<\/strong> Hi\u1ec7u \u1ee9ng PMD l\u00e0 <strong>mang t\u00ednh th\u1ed1ng k\u00ea<\/strong> v\u00e0 t\u00edch l\u0169y theo <strong>c\u0103n b\u1eadc hai c\u1ee7a kho\u1ea3ng c\u00e1ch<\/strong>. M\u1ed9t v\u1ea5n \u0111\u1ec1 g\u1ea7n nh\u01b0 kh\u00f4ng nh\u1eadn th\u1ea5y tr\u00ean qu\u00e3ng \u0111\u01b0\u1eddng 10 km c\u00f3 th\u1ec3 tr\u1edf n\u00ean th\u1ea3m kh\u1ed1c tr\u00ean qu\u00e3ng \u0111\u01b0\u1eddng 1000 km.<\/p><\/li><li><p style=\"margin: 0px;\"><strong>Thay \u0111\u1ed5i m\u00f4i tr\u01b0\u1eddng \u0111\u1ed9ng:<\/strong> PMD kh\u00f4ng t\u0129nh. Gi\u00e1 tr\u1ecb c\u1ee7a n\u00f3 thay \u0111\u1ed5i theo dao \u0111\u1ed9ng nhi\u1ec7t \u0111\u1ed9, rung \u0111\u1ed9ng c\u01a1 h\u1ecdc v\u00e0 \u1ee9ng su\u1ea5t c\u01a1 h\u1ecdc t\u00e1c \u0111\u1ed9ng l\u00ean c\u00e1p. \u0110i\u1ec1u n\u00e0y khi\u1ebfn PMD tr\u1edf th\u00e0nh m\u1ed9t \u201cm\u1ee5c ti\u00eau di \u0111\u1ed9ng\u201d, kh\u00f3 b\u00f9 tr\u1eeb b\u1eb1ng c\u00e1c gi\u1ea3i ph\u00e1p c\u1ed1 \u0111\u1ecbnh \u0111\u01a1n gi\u1ea3n.<\/p><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" ><strong>\u27a4 C\u00e1c th\u00f4ng s\u1ed1 v\u00e0 tham s\u1ed1 PMD ch\u1ee7 ch\u1ed1t<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ec3 hi\u1ec3u c\u00e1c \u0111\u1eb7c t\u1ea3 PMD, b\u1ea1n s\u1ebd g\u1eb7p c\u00e1c thu\u1eadt ng\u1eef then ch\u1ed1t sau:<\/p>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\"><p>Thu\u1eadt ng\u1eef<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Vi\u1ebft t\u1eaft<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>\u0110\u1ecbnh ngh\u0129a<br><\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>V\u00ec sao \u0111i\u1ec1u n\u00e0y quan tr\u1ecdng<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p><strong>\u0110\u1ed9 tr\u1ec5 nh\u00f3m vi ph\u00e2n<\/strong><\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>DGD<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>\u0110\u1ed9 tr\u1ec5 th\u1eddi gian t\u1ee9c th\u1eddi gi\u1eefa hai ch\u1ebf \u0111\u1ed9 ph\u00e2n c\u1ef1c.<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Kh\u1ed1i x\u00e2y d\u1ef1ng c\u01a1 b\u1ea3n c\u1ee7a PMD; gi\u00e1 tr\u1ecb n\u00e0y thay \u0111\u1ed5i ng\u1eabu nhi\u00ean theo th\u1eddi gian.<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p><strong>H\u1ec7 s\u1ed1 PMD<\/strong><\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>\u2013<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Ch\u1ec9 s\u1ed1 \u0111\u00e1nh gi\u00e1 ch\u1ea5t l\u01b0\u1ee3ng s\u1ee3i quang, \u0111\u01b0\u1ee3c bi\u1ec3u th\u1ecb b\u1eb1ng ps\/\u221akm.<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>D\u1ef1 \u0111o\u00e1n m\u1ee9c \u0111\u1ed9 PMD t\u00edch l\u0169y tr\u00ean m\u1ed9t chi\u1ec1u d\u00e0i s\u1ee3i quang nh\u1ea5t \u0111\u1ecbnh. Gi\u00e1 tr\u1ecb th\u1ea5p h\u01a1n l\u00e0 t\u1ed1t h\u01a1n.<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p><strong>PMD c\u1ee7a tuy\u1ebfn c\u00e1p<\/strong><\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>\u2013<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>T\u1ed5ng PMD cho m\u1ed9t \u0111o\u1ea1n s\u1ee3i quang c\u1ee5 th\u1ec3.<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Gi\u00e1 tr\u1ecb then ch\u1ed1t m\u00e0 k\u1ef9 s\u01b0 s\u1eed d\u1ee5ng \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh li\u1ec7u m\u1ed9t tuy\u1ebfn c\u00e1p c\u00f3 h\u1ed7 tr\u1ee3 \u0111\u01b0\u1ee3c t\u1ed1c \u0111\u1ed9 d\u1eef li\u1ec7u mong mu\u1ed1n hay kh\u00f4ng.<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p><strong>DGD trung b\u00ecnh<\/strong><\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>\u2013<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Gi\u00e1 tr\u1ecb trung b\u00ecnh c\u1ee7a DGD theo th\u1eddi gian.<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>\u0110\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 \u01b0\u1edbc t\u00ednh x\u00e1c su\u1ea5t gi\u00e1n \u0111o\u1ea1n h\u1ec7 th\u1ed1ng do PMD.<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" ><strong>\u27a4 C\u00e1ch kh\u1eafc ph\u1ee5c PMD: C\u00e1c chi\u1ebfn l\u01b0\u1ee3c v\u00e0 gi\u1ea3i ph\u00e1p<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Gi\u1ea3m thi\u1ec3u PMD \u0111\u00f2i h\u1ecfi m\u1ed9t c\u00e1ch ti\u1ebfp c\u1eadn \u0111a t\u1ea7ng:<\/p>\n\n\n\n<ol class=\"wp-block-list\" >\n<li><p style=\"margin: 0px;\"><strong>S\u1eed d\u1ee5ng s\u1ee3i quang c\u00f3 PMD th\u1ea5p:<\/strong> C\u00e1c lo\u1ea1i s\u1ee3i quang m\u1edbi \u0111\u01b0\u1ee3c s\u1ea3n xu\u1ea5t theo c\u00e1c ti\u00eau chu\u1ea9n ch\u1eb7t ch\u1ebd h\u01a1n nhi\u1ec1u, v\u1edbi h\u1ec7 s\u1ed1 PMD d\u01b0\u1edbi <strong>0,1 ps\/\u221akm<\/strong> ho\u1eb7c th\u1eadm ch\u00ed <strong>0,05 ps\/\u221akm<\/strong>.<\/p><\/li><li><p style=\"margin: 0px;\"><strong>B\u1ed9 b\u00f9 PMD quang h\u1ecdc (PMDC):<\/strong> \u0110\u00e2y l\u00e0 c\u00e1c thi\u1ebft b\u1ecb chuy\u00ean d\u1ee5ng \u0111\u01b0\u1ee3c \u0111\u1eb7t n\u1ed1i ti\u1ebfp \u0111\u1ec3 t\u1ea1o ra \u0111\u1ed9 tr\u1ec5 ph\u00e2n c\u1ef1c ch\u00eanh l\u1ec7ch (DGD) b\u1eb1ng v\u00e0 ng\u01b0\u1ee3c pha nh\u1eb1m tri\u1ec7t ti\u00eau PMD c\u1ee7a s\u1ee3i quang. C\u00e1c thi\u1ebft b\u1ecb n\u00e0y hi\u1ec7u qu\u1ea3 nh\u01b0ng c\u00f3 th\u1ec3 ph\u1ee9c t\u1ea1p v\u00e0 t\u1ed1n k\u00e9m.<\/p><\/li><li><p style=\"margin: 0px;\"><strong>C\u00e1c \u0111\u1ecbnh d\u1ea1ng \u0111i\u1ec1u ch\u1ebf n\u00e2ng cao &amp; X\u1eed l\u00fd t\u00edn hi\u1ec7u s\u1ed1 (DSP):<\/strong> Gi\u1ea3i ph\u00e1p m\u1ea1nh m\u1ebd v\u00e0 hi\u1ec7n \u0111\u1ea1i nh\u1ea5t n\u1eb1m ngay trong <strong>ch\u00ednh b\u1ed9 thu ph\u00e1t<\/strong>. Quang h\u1ecdc \u0111\u1ed3ng pha s\u1eed d\u1ee5ng c\u00e1c k\u1ef9 thu\u1eadt \u0111i\u1ec1u ch\u1ebf ti\u00ean ti\u1ebfn (v\u00ed d\u1ee5: DP-QPSK, DP-16QAM) v\u00e0 c\u00e1c thu\u1eadt to\u00e1n m\u1ea1nh m\u1ebd <a target=\"_blank\" rel=\"\" href=\"https:\/\/resourceslp.szlogic.cn\/vi\/glossary\/digital-signal-processor-functionality-in-optical-transceivers\/\"><strong>X\u1eed l\u00fd t\u00edn hi\u1ec7u s\u1ed1 (DSP)<\/strong><\/a> c\u00f3 th\u1ec3 b\u00f9 tr\u1eeb \u0111i\u1ec7n t\u1eed m\u1ed9t l\u01b0\u1ee3ng l\u1edbn PMD, nh\u1edd \u0111\u00f3 tr\u1edf n\u00ean v\u1ed1n d\u0129 b\u1ec1n b\u1ec9 tr\u01b0\u1edbc PMD.<\/p><\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u00e2y l\u00e0 l\u00fac vi\u1ec7c l\u1ef1a ch\u1ecdn module quang ph\u00f9 h\u1ee3p tr\u1edf th\u00e0nh y\u1ebfu t\u1ed1 quan tr\u1ecdng nh\u1ea5t \u0111\u1ec3 <strong>kh\u1eafc ph\u1ee5c c\u00e1c th\u00e1ch th\u1ee9c do PMD g\u00e2y ra trong c\u00e1c trung t\u00e2m d\u1eef li\u1ec7u t\u1ed1c \u0111\u1ed9 cao v\u00e0 m\u1ea1ng truy\u1ec1n t\u1ea3i 5G<\/strong>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" ><strong>\u27a4 K\u1ebft lu\u1eadn: \u0110\u1eebng \u0111\u1ec3 PMD l\u00e0m ch\u1eadm m\u1ea1ng c\u1ee7a b\u1ea1n<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u0110\u1ed9 t\u00e1n s\u1eafc ph\u00e2n c\u1ef1c (Polarization Mode Dispersion \u2013 PMD)<\/strong> l\u00e0 m\u1ed9t hi\u1ec7n t\u01b0\u1ee3ng v\u1eadt l\u00fd c\u01a1 b\u1ea3n m\u00e0 nay kh\u00f4ng th\u1ec3 b\u1ecf qua. Khi ch\u00fang ta \u0111\u1ea9y gi\u1edbi h\u1ea1n v\u1ec1 t\u1ed1c \u0111\u1ed9 v\u00e0 kho\u1ea3ng c\u00e1ch, vi\u1ec7c hi\u1ec3u r\u00f5 v\u00e0 gi\u1ea3m thi\u1ec3u PMD l\u00e0 \u0111i\u1ec1u thi\u1ebft y\u1ebfu \u0111\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c hi\u1ec7u n\u0103ng m\u1ea1ng \u0111\u00e1ng tin c\u1eady.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1eb1ng c\u00e1ch \u0111\u1ea7u t\u01b0 v\u00e0o s\u1ee3i quang ch\u1ea5t l\u01b0\u1ee3ng cao v\u00e0, quan tr\u1ecdng h\u01a1n c\u1ea3, l\u1ef1a ch\u1ecdn c\u00e1c <a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/store-25432-optics-transceivers-sfp-modules.htm\"><strong>b\u1ed9 thu ph\u00e1t quang<\/strong><\/a> module quang th\u00f4ng minh c\u00f3 t\u00edch h\u1ee3p kh\u1ea3 n\u0103ng b\u00f9 PMD m\u1ea1nh m\u1ebd, b\u1ea1n c\u00f3 th\u1ec3 \u0111\u1ea3m b\u1ea3o c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng c\u1ee7a m\u00ecnh s\u1eb5n s\u00e0ng \u0111\u00e1p \u1ee9ng nhu c\u1ea7u c\u1ee7a ng\u00e0y mai.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" ><strong>\u0111\u1ec3 \u0111\u01b0\u1ee3c t\u01b0 v\u1ea5n c\u00e1 nh\u00e2n h\u00f3a v\u00e0 kh\u00e1m ph\u00e1 s\u1ea3n ph\u1ea9m c\u1ee7a ch\u00fang t\u00f4i<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" >\u0110\u1ed9 t\u00e1n s\u1eafc ph\u00e2n c\u1ef1c l\u00e0 g\u00ec, gi\u1ea3i th\u00edch m\u1ed9t c\u00e1ch \u0111\u01a1n gi\u1ea3n?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u1ed9 t\u00e1n s\u1eafc ch\u1ebf \u0111\u1ed9 ph\u00e2n c\u1ef1c x\u1ea3y ra khi \u00e1nh s\u00e1ng di chuy\u1ec3n v\u1edbi c\u00e1c t\u1ed1c \u0111\u1ed9 kh\u00e1c nhau. M\u1ed7i ch\u1ebf \u0111\u1ed9 ph\u00e2n c\u1ef1c lan truy\u1ec1n theo c\u00e1ch ri\u00eang c\u1ee7a n\u00f3. \u0110i\u1ec1u n\u00e0y khi\u1ebfn t\u00edn hi\u1ec7u b\u1ecb m\u1edd v\u00e0 \u0111\u1ebfn \u0111\u00edch v\u00e0o nh\u1eefng th\u1eddi \u0111i\u1ec3m kh\u00e1c nhau.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >PMD g\u00e2y ra nh\u1eefng v\u1ea5n \u0111\u1ec1 g\u00ec trong m\u1ea1ng c\u00e1p quang?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">PMD c\u00f3 th\u1ec3 khi\u1ebfn d\u1eef li\u1ec7u c\u1ee7a b\u1ea1n kh\u00f3 \u0111\u1ecdc h\u01a1n. C\u00e1c t\u00edn hi\u1ec7u c\u00f3 th\u1ec3 tr\u1ed9n l\u1eabn ho\u1eb7c ch\u1ed3ng l\u1ea5n l\u00ean nhau. B\u1ea1n c\u00f3 th\u1ec3 th\u1ea5y nhi\u1ec1u l\u1ed7i h\u01a1n ho\u1eb7c t\u1ed1c \u0111\u1ed9 m\u1ea1ng ch\u1eadm \u0111i.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >B\u1ea1n c\u00f3 th\u1ec3 l\u00e0m g\u00ec \u0111\u1ec3 gi\u1ea3m PMD?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1ea1n c\u00f3 th\u1ec3 ch\u1ecdn c\u00e1c s\u1ee3i quang c\u00f3 thi\u1ebft k\u1ebf t\u1ed1t h\u01a1n. C\u00e1c s\u1ee3i quang duy tr\u00ec ph\u00e2n c\u1ef1c gi\u00fap gi\u1ea3m PMD. Vi\u1ec7c ki\u1ec3m tra th\u01b0\u1eddng xuy\u00ean v\u00e0 s\u1eed d\u1ee5ng c\u00e1c thi\u1ebft b\u1ecb chuy\u00ean d\u1ee5ng c\u0169ng gi\u00fap ki\u1ec1m ch\u1ebf PMD.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Nh\u1eefng c\u00f4ng c\u1ee5 n\u00e0o \u0111o PMD trong s\u1ee3i quang?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">B\u1ea1n s\u1eed d\u1ee5ng c\u00e1c m\u00e1y ki\u1ec3m tra nh\u01b0 giao thoa k\u1ebf ho\u1eb7c b\u1ed9 ph\u00e2n t\u00edch d\u1ecbch pha. Nh\u1eefng c\u00f4ng c\u1ee5 n\u00e0y cho bi\u1ebft m\u1ee9c \u0111\u1ed9 tr\u1ec5 do PMD g\u00e2y ra trong s\u1ee3i quang c\u1ee7a b\u1ea1n.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Gi\u00e1 tr\u1ecb PMD th\u1ea5p c\u00f3 \u00fd ngh\u0129a g\u00ec \u0111\u1ed1i v\u1edbi m\u1ea1ng c\u1ee7a b\u1ea1n?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Gi\u00e1 tr\u1ecb PMD th\u1ea5p gi\u00fap t\u00edn hi\u1ec7u lu\u00f4n r\u00f5 r\u00e0ng. B\u1ea1n c\u00f3 th\u1ec3 truy\u1ec1n d\u1eef li\u1ec7u nhanh h\u01a1n v\u00e0 m\u1eafc \u00edt l\u1ed7i h\u01a1n. M\u1ea1ng c\u1ee7a b\u1ea1n duy tr\u00ec \u0111\u1ed9 \u1ed5n \u0111\u1ecbnh cao v\u00e0 ho\u1ea1t \u0111\u1ed9ng hi\u1ec7u qu\u1ea3.<\/p>","protected":false},"excerpt":{"rendered":"<p>Polarization mode dispersion in fiber optics causes signal distortion and limits data speed. Understand PMD&#8217;s impact and how to manage it in modern networks.<\/p>","protected":false},"author":1,"featured_media":4005,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[27],"tags":[26],"class_list":["post-4007","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-glossary","tag-optics-transceivers"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/posts\/4007","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/comments?post=4007"}],"version-history":[{"count":3,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/posts\/4007\/revisions"}],"predecessor-version":[{"id":9376,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/posts\/4007\/revisions\/9376"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/media\/4005"}],"wp:attachment":[{"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/media?parent=4007"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/categories?post=4007"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/resourceslp.szlogic.cn\/vi\/wp-json\/wp\/v2\/tags?post=4007"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}