Measurment and Analysis on Noise and Distortion Properties of Cascaded AM Optic Links

摘要

Since AM optic links differ from coaxial cable systems, the addition of distortion products is more complicated and factors of cascading are also different. The noise and distortion properties of AM repeater links with DFB lasers will be discussed in this paper.Having made measurement and analysis on the CNRs, GTBs and CSOs of different factory's DFB cascades, we suggest that the cascaded CTB and CSO add on a "10Lg" basis. That is, if each AM optic system have the same distortion properties, the CTB and CSO of a cascade of 2 DFBs will degrade by 4.5 dB(15Lg=4.5). The cascaded CNR still add on a "10Lg" basis.