{"id":3910,"date":"2026-09-10T03:43:06","date_gmt":"2026-09-10T03:43:06","guid":{"rendered":"https:\/\/firstfibertech.com\/?p=3910"},"modified":"2026-09-10T04:15:10","modified_gmt":"2026-09-10T04:15:10","slug":"%e7%aa%81%e7%a0%b4%e5%be%ae%e8%a7%82%e7%89%a9%e7%90%86%e5%ad%a6%e4%b8%8e%e4%bf%a1%e6%81%af%e8%ae%ba%e7%9a%84%e7%95%8c%e9%99%90%ef%bc%9a%e4%bd%8e%e9%98%b6otdr%e7%a0%94%e5%8f%91%e4%b8%ad%e7%9a%84","status":"publish","type":"post","link":"https:\/\/firstfibertech.com\/zh\/blog\/breaking-the-boundaries-of-micro-physics-and-information-theory-extreme-challenges-and-generational-opportunities-in-low-level-otdr-rd\/","title":{"rendered":"\u7a81\u7834\u5fae\u7269\u7406\u5b66\u4e0e\u4fe1\u606f\u7406\u8bba\u7684\u754c\u9650\uff1aOTDR\u7814\u53d1\u4e2d\u7684\u6781\u7aef\u6311\u6218\u4e0e\u4e16\u4ee3\u673a\u9047"},"content":{"rendered":"

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\u8be5 <\/strong>R<\/mi>f<\/mi><\/msub>\u2212<\/mo>C<\/mi>p<\/mi><\/msub><\/mrow>R_f \u2013 C_p<\/annotation><\/semantics><\/math> \u8de8\u963b\u653e\u5927\u5668\uff08TIA\uff09\u7684\u201c\u5bc4\u751f\u6781\u6096\u8bba\u201d<\/strong> \u4e3a\u4e86\u6291\u5236\u70ed\u566a\u58f0\u7535\u6d41 I<\/mi>n<\/mi><\/msub>=<\/mo>4<\/mn>k<\/mi>T<\/mi>\u0394<\/mi><\/mrow>f<\/mi><\/mrow>R<\/mi>f<\/mi><\/msub><\/mfrac><\/msqrt><\/mrow>I_n = \\sqrt{\\frac{4kT\\Delta f}{R_f}}<\/annotation><\/semantics><\/math> \u8de8\u963b\u653e\u5927\u5668\uff08TIA\uff09\u7684\u53cd\u9988\u7535\u963b R<\/mi>f<\/mi><\/msub>R_f<\/annotation><\/semantics><\/math> \u5fc5\u987b\u5927\u5e45\u589e\u52a0\u3002\u7136\u800c\uff0c, R<\/mi>f<\/mi><\/msub>R_f<\/annotation><\/semantics><\/math>, \uff0c\u518d\u52a0\u4e0aAPD\u7ed3\u7535\u5bb9 C<\/mi>p<\/mi>d<\/mi><\/mrow><\/msub>C_{pd}<\/annotation><\/semantics><\/math> \u4ee5\u53ca\u8fd0\u7b97\u653e\u5927\u5668\u7684\u8f93\u5165\u5bc4\u751f\u7535\u5bb9 C<\/mi>i<\/mi>n<\/mi><\/mrow><\/msub>C_{in}<\/annotation><\/semantics><\/math>, \u4ea7\u751f\u4e00\u4e2a\u4f4e\u9891\u6781\u70b9 f<\/mi>\u2212<\/mo>3<\/mn>d<\/mi>B<\/mi><\/mrow><\/msub>=<\/mo>1<\/mn>2<\/mn>\u03c0<\/mi>R<\/mi>f<\/mi><\/msub>(<\/mo>C<\/mi>p<\/mi>d<\/mi><\/mrow><\/msub>+<\/mo>C<\/mi>i<\/mi>n<\/mi><\/mrow><\/msub>)<\/mo><\/mrow><\/mfrac><\/mrow>f_{-3dB} = \\frac{1}{2\\pi R_f (C_{pd} + C_{in})}<\/annotation><\/semantics><\/math>. \u901a\u8fc7 C<\/mi>p<\/mi><\/msub>C_p<\/annotation><\/semantics><\/math> \u5f80\u5f80\u8fbe\u5230\u597d\u51e0\u4e2a p<\/mi>F<\/mi><\/mrow>pF<\/annotation><\/semantics><\/math>, \uff0c\u63d0\u9ad8\u7075\u654f\u5ea6\u4e0d\u53ef\u907f\u514d\u5730\u4f1a\u727a\u7272\u5e26\u5bbd\uff08\u5bfc\u81f4\u7a7a\u95f4\u5206\u8fa8\u7387\u53d8\u5dee\uff09\u3002\u5229\u7528\u611f\u5e94\u5cf0\u503c\u6216\u81ea\u4e3e\u7b49\u7535\u8def\u62d3\u6251\u6765\u62b5\u6d88\u5bc4\u751f\u7535\u5bb9\uff0c\u4ecd\u7136\u662f\u6a21\u62df\u96c6\u6210\u7535\u8def\u8bbe\u8ba1\u4e2d\u4e00\u9879\u6781\u5177\u6311\u6218\u6027\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n

APD\u4e2d\u7684\u6df1\u80fd\u7ea7\u9677\u9631\u4e0e\u6709\u6e90\u94b3\u4f4d\uff1a<\/strong> \u5f3a\u53cd\u5c04\u76f2\u533a\u65e0\u6cd5\u4ec5\u901a\u8fc7\u7f29\u77ed\u7cfb\u7edf\u5e26\u5bbd\u6765\u89e3\u51b3\u3002\u5f53InGaAs\/InP APD\u9047\u5230\u5f3a\u5149\u65f6\uff0cInP\u500d\u589e\u5c42\u4e2d\u7684\u201c\u6df1\u80fd\u7ea7\u9677\u9631\u201d\u4f1a\u6355\u83b7\u5e76\u7f13\u6162\u91ca\u653e\u7a7a\u7a74\u8f7d\u6d41\u5b50\uff0c\u4ece\u800c\u5f62\u6210\u201c\u5c3e\u968f\u6548\u5e94\u201d\uff0c\u8fd9\u79cd\u6548\u5e94\u4ece\u7269\u7406\u4e0a\u8bb2\u65e0\u6cd5\u76f4\u63a5\u6d88\u9664\u3002 \u91c7\u7528\u8096\u7279\u57fa\u4e8c\u6781\u7ba1\u7684\u4f20\u7edf\u88ab\u52a8\u94b3\u4f4d\u6280\u672f\u5df2\u8fbe\u5230\u74f6\u9888\u3002\u5fc5\u987b\u5f15\u5165\u54cd\u5e94\u65f6\u95f4\u5728\u4e9a\u7eb3\u79d2\u7ea7\u4ee5\u5185\u7684\u6709\u6e90\u6dec\u706d\u7535\u8def\uff0c\u751a\u81f3\u52a8\u6001\u964d\u4f4eAPD\u504f\u7f6e\u7535\u538b\uff08V<\/mi>b<\/mi>i<\/mi>a<\/mi>s<\/mi><\/mrow><\/msub>V_{bias}<\/annotation><\/semantics><\/math>) \u5728\u5f3a\u53cd\u5c04\u671f\u95f4\uff0c\u4ee5\u6291\u5236\u96ea\u5d29\u6548\u5e94\u3002<\/p>\n\n\n\n

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\u6d88\u5149\u6bd4\uff08ER\uff09\u548c\u70ed\u6f02\u79fb\u7684\u6bc1\u706d\u6027\u5f71\u54cd\uff1a<\/strong> \u5b9e\u73b0\u4e92\u8865\u6208\u83b1\u7801\u901a\u5e38\u9700\u8981\u4f20\u8f93\u7801 A<\/mi>A<\/annotation><\/semantics><\/math> \u53ca\u5176\u8865\u96c6 A<\/mi>\u203e<\/mo><\/mover>\\bar{A}<\/annotation><\/semantics><\/math>. \u5982\u679c\u534a\u5bfc\u4f53\u6fc0\u5149\u5668\uff08LD\uff09\u6216\u5916\u90e8\u9a6c\u8d6b-\u66fe\u5fb7\u5c14\u8c03\u5236\u5668\uff08MZM\uff09\u7684\u6d88\u5149\u6bd4\u4e0d\u8db3\uff0c\u6216\u8005\u57fa\u7ebf\u5149\u529f\u7387\u53d1\u751f\u6f02\u79fb\uff0c\u54ea\u6015\u53ea\u662f 0.1<\/mn>%<\/mi><\/mrow>0.1\\%<\/annotation><\/semantics><\/math> \u5728\u4f20\u8f93\u8fc7\u7a0b\u4e2d\uff0c\u7531\u4e8e\u81ea\u70ed\u6548\u5e94\uff0c\u6b63\u4ea4\u7801\u7684\u4e92\u76f8\u5173\u65c1\u74e3\u65e0\u6cd5\u5f52\u96f6\u3002\u8fd9\u4e9b\u6b8b\u4f59\u65c1\u74e3\u5728OTDR\u6ce2\u5f62\u56fe\u4e0a\u8868\u73b0\u4e3a\u5bc6\u96c6\u7684\u201c\u865a\u5047\u5cf0\u201d\uff0c\u8fd9\u4e0d\u4ec5\u65e0\u6cd5\u63d0\u9ad8\u52a8\u6001\u8303\u56f4\uff0c\u800c\u4e14\u5f7b\u5e95\u7834\u574f\u4e86\u6d4b\u8bd5\u57fa\u7ebf\u7684\u7ebf\u6027\u3002<\/p>\n\n\n\n

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Y<\/mi>(<\/mo>t<\/mi>)<\/mo>=<\/mo>\u222b<\/mo>S<\/mi>(<\/mo>t<\/mi>\u2212<\/mo>\u03c4<\/mi>)<\/mo>X<\/mi>(<\/mo>\u03c4<\/mi>)<\/mo>d<\/mi>\u03c4<\/mi>+<\/mo>N<\/mi>(<\/mo>t<\/mi>)<\/mo><\/mrow>Y(t) = \\int S(t-\\tau)X(\\tau) d\\tau + N(t)<\/annotation><\/semantics><\/math><\/p>\n\n\n\n

\u8fd9\u662f\u4e00\u4e2a\u5178\u578b\u7684\u75c5\u6001\u53cd\u95ee\u9898\uff1a\u7cfb\u7edf\u7684\u4f20\u9012\u51fd\u6570 S<\/mi>(<\/mo>t<\/mi>)<\/mo><\/mrow>S(t)<\/annotation><\/semantics><\/math> \u5728\u9ad8\u9891\u57df\u4e2d\u901a\u5e38\u5448\u6307\u6570\u8870\u51cf\uff0c\u800c\u566a\u58f0 N<\/mi>(<\/mo>t<\/mi>)<\/mo><\/mrow>N(t)<\/annotation><\/semantics><\/math> \u662f\u5bbd\u5e26\u4e14\u5747\u5300\u5206\u5e03\u7684\u3002<\/p>\n\n\n\n

\u6267\u884c\u9006\u8fd0\u7b97\u65f6 X<\/mi>^<\/mo><\/mover>(<\/mo>f<\/mi>)<\/mo>=<\/mo>Y<\/mi>(<\/mo>f<\/mi>)<\/mo><\/mrow>S<\/mi>(<\/mo>f<\/mi>)<\/mo><\/mrow><\/mfrac><\/mrow>\\hat{X}(f) = \\frac{Y(f)}{S(f)}<\/annotation><\/semantics><\/math> \u5728\u9891\u57df\u4e2d\uff0c\u9ad8\u9891\u533a\u57df\u4e2d\u5fae\u5c0f\u7684\u70ed\u566a\u58f0\u4f1a\u88ab\u653e\u5927\u6570\u5343\u500d\u3002<\/p>\n\n\n\n

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\u7a81\u7834\u4f20\u7edf\u754c\u9650\u7684\u65b0\u4e00\u4ee3\u8303\u5f0f<\/h2>\n\n\n\n

\u4ece\u5f3a\u5ea6\u68c0\u6d4b\u5230\u5149\u573a\u68c0\u6d4b\u7684\u53d1\u5c55\uff1a\u76f8\u5e72OTDR\uff08C-OTDR\uff09\u4e0e\u745e\u5229\u8870\u843d\u8865\u507f<\/h3>\n\n\n\n

\u968f\u7740\u76f4\u63a5\u68c0\u6d4b\u9010\u6e10\u63a5\u8fd1\u5355\u7c92\u5b50\u566a\u58f0\u6781\u9650\uff0c\u5f15\u5165\u672c\u5730\u632f\u8361\u5668\uff08LO\uff09\u4ee5\u5b9e\u73b0\u76f8\u5e72\u68c0\u6d4b\u4fbf\u6210\u4e3a\u5fc5\u7136\u4e4b\u4e3e\u3002\u901a\u8fc7\u5229\u7528\u5f02\u9891\u632f\u8361\u5e72\u6d89\uff0cC-OTDR \u53ef\u5c06\u4fe1\u566a\u6bd4\uff08SNR\uff09\u63d0\u9ad8\u8d85\u8fc7 20<\/mn> dB<\/mtext><\/mrow>20\\text{ dB}<\/annotation><\/semantics><\/math> \u4e0e\u76f4\u63a5\u63a2\u6d4b\u76f8\u6bd4\uff0c\u5b83\u80fd\u8f7b\u677e\u7a7f\u900f\u6570\u5343\u516c\u91cc\u7684\u6d77\u5e95\u7535\u7f06\u3002<\/p>\n\n\n\n

\u6838\u5fc3\u673a\u9047\u4e0e\u6311\u6218\uff1a<\/strong> \u76f8\u5e72\u7cfb\u7edf\u7684\u7edd\u5bf9\u96be\u5ea6\u662f \u745e\u5229\u8870\u51cf<\/strong>. \u7531\u4e8e\u5149\u7684\u9ad8\u76f8\u5e72\u6027\uff0c\u5149\u7ea4\u5185\u7684\u5fae\u6563\u5c04\u4e2d\u5fc3\u4f1a\u5f15\u8d77\u968f\u673a\u7684\u76f8\u5e72\u5e72\u6d89\uff0c\u4ece\u800c\u4ea7\u751f\u6df1\u5ea6\u53ef\u8fbe\u6570\u5341\u5206\u8d1d\u7684\u6591\u70b9\u566a\u58f0\u3002\u7814\u53d1\u56e2\u961f\u5fc5\u987b\u91c7\u7528 \u9891\u7387\u9636\u8dc3\u8109\u51b2<\/strong> \u6216 \u5541\u557e\u8109\u51b2<\/strong>\uff0c\u5e76\u5728\u540e\u5904\u7406\u6570\u5b57\u4fe1\u53f7\u5904\u7406\uff08DSP\uff09\u4e2d\u8fdb\u884c\u9891\u8c31\u6b63\u4ea4\u89e3\u8c03\u548c\u975e\u76f8\u5e72\u5e73\u5747\u3002\u8fd9\u5c06\u68d8\u624b\u7684\u8870\u843d\u566a\u58f0\u8f6c\u5316\u4e3a\u6781\u5177\u4ef7\u503c\u7684\u5206\u5e03\u5f0f\u58f0\u5b66\/\u632f\u52a8\u4f20\u611f\u4fe1\u53f7\uff0c\u4ece\u800c\u5c06OTDR\u5e02\u573a\u76f4\u63a5\u4ece\u7535\u4fe1\u6d4b\u8bd5\u62d3\u5c55\u81f3\u5b89\u5168\u5468\u754c\u3001\u5730\u9707\u76d1\u6d4b\u4ee5\u53ca\u5de5\u4e1a\u7269\u8054\u7f51\u9886\u57df\u3002<\/p>\n\n\n\n

\u6765\u81ea\u91cf\u5b50\u6781\u9650\u7684\u7ef4\u5ea6\u51b2\u51fb\uff1a\u5355\u5149\u5b50\u5149\u65f6\u57df\u53cd\u5c04\u4eea\uff08SPAD\/TCSPC\uff09<\/h3>\n\n\n\n

\u901a\u8fc7\u91c7\u7528\u5355\u5149\u5b50\u96ea\u5d29\u4e8c\u6781\u7ba1\uff08SPAD\uff09\u548c\u65f6\u95f4\u76f8\u5173\u5355\u5149\u5b50\u8ba1\u6570\uff08TCSPC\uff09\u6280\u672f\uff0c\u8be5OTDR\u7684\u63a5\u6536\u673a\u5236\u5df2\u4ece\u201c\u6a21\u62df\u7535\u6d41\u79ef\u5206\u201d\u5b8c\u5168\u8f6c\u53d8\u4e3a\u201c\u79bb\u6563\u91cf\u5b50\u7edf\u8ba1\u201d\u3002<\/p>\n\n\n\n