Abstract

In the thesis, we investigate and analyze the impact of Raman crosstalk and RIN transfer on RF video overlay channels induced by 1490-nm optical intensity modulated digital data channel, considering modulation formats of non-return-to-zero (NRZ), return-to-zero (RZ), Inverse-RZ (IRZ), and Manchester coding, fiber length, optical power, optical modulation index and fiber polarization mode dispersion (PMD). Firstly, carrier to noise ration (CNR) degradation due to the worst and best Raman crosstalk due to the Raman crosstalk is compared for NRZ, RZ, inverse RZ and Manchester. It is found that Raman crosstalk is reduced significantly when inverse RZ or Manchester is used, in contrast to NRZ and RZ. By comparing the result of CNR degradation in a real fiber with PMD, it is found that orthogonal polarization state setting at fiber input is still helpful in the reduction of Raman crosstalk for NRZ and RZ, but hardly for inverse RZ and Manchester, if fiber length is less than 15 km, and otherwise useless due to PMD of fiber. Also, relative intensity noise (RIN) transfer induced CNR degradation is analyzed and is too small to be considered.