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tv Optical QotchoHpu' chep Modulation poj

Nov 25, 2014

'e' lu' De' neH yotlh 'ul processing neH optical fiber QumpIn, QuQ electrical signals bIDameH vaj signals optical, so as to yotlhmeyvo' fiber DISov Hoch. pa' optical fiber QumpIn pat, yu'egh carrier qeng, De' chep joq tlhuD pong led ld modulated De' load vaj yu'egh chep mIw. bIDameH optical modulator vo' electrical signal optical signal jan chav.

roD wav modulation vaj cha' categories, namely analog 'ej digital modulation.

analog modulation pa' cha' Segh, wa' chep Hal intensity modulation (d-im) analog baseband signals Hoch wo'; latlh lo' joq taH pagh pulse chaDvay' (rf) subcarrier je, amplitude, Se' phase pagh modulation, etc., signal baseband wa'DIch analog 'ej vaj subject subcarrier modulation intensity modulation Hal. 'utmo' Dujvam analog modulation nap luch, ghajchugh Human leSpal bandwidth, 'ach vIvup yIqaw interference ghorgh wab cumulative relay.

digital modulation modulation scheme fiber optical 'elbogh QumpIn, qaSpu'DI' analog signal quantized binary digital signal "1" pagh "0"-DoH modulate optical carrier 'ej pulse ngoq (pcm) sampling. 'utmo' Dujvam digital modulation anti-interference laH, Sov wIHutlh wej vI' wab relay dispersion je, vaj chuq nI' transmission, laH chav SoH disadvantage nIS wider Se' ghom, jan je Qatlh.

relations modulation press chep Hal lang, jaS cha' bIquv direct modulation 'ej external modulation. refers yInbe'taHbogh direct electrical modulation signal SeH Hal (chep intensity, Se', etc.) optical Se' am lotvam pagh fm joq joq, modulation internal modulation bogh je Sov law' Hoch wo' QotchoHpu' optical QotchoHpu' modulated wov pong wov oscillation parameters semiconductor; be'ghomDaq 'Iv equal amplitude output tlheD 'ej modulated Se' choHbe' mIw vIHechbogh optical carrier pong optical modulator, optical signal vegh optical modulator amplitude, Se' je phase carrier chav 'ej latlh qabDaq 'utmo' Dujvam direct modulation Hal chep nap 'ach chaw', modulation rate vuS (such as Se' chirp, etc.) degradation carrier lifetime 'ej high-speed rates. external modulation modulator, Qatlh tlham 'ach pov modulation yIqaw availability poQ, especially yuQmeyDaq lo' DeSDu' jen speed, jan je known je externally modulate optical QotchoHpu'.

optical joq parameters lang modulated press: intensity modulation, phase modulation, polarization modulation.

currently rav widely lo' neH optical fiber QumpIn chep Hal direct intensity modulation, subcarrier intensity modulation 'ej digital modulation, external modulation DeSDu' jen rates waw'.

chep Hal SeH circuit

pat requirements jen chep Hal, comprising:

1. wavelength stability requirements: requirement jen ghaj wdm chep 'uchtaH wavelength stability pat, ghot'e' wavelength shift qaStaHvIS SabtaHbogh channels crosstalk.

2. HoS stability requirements: transmission yIqaw channel wej neH Sov wIHutlh channel HoS vIHech, 'ej vegh 'angbogh Da transient latlh channels yIqaw mup edfa.

Hat SeH HoS je SeH circuit DaH nobvam chep Hal SeH circuit, role Hat tuq qun 'angbogh Da aging jan, QotchoHpu' stability yIqaw 'ej eliminate. latlh Hal je slow start SeH circuit protection circuit, 'uD reverse jer Qu'mey potlh protection circuit, Qu'mey over-potlh protection circuit 'ej 'uD 'uD shutdown circuit.