Optical Frequency Comb Generation And Its Applications In Next Generation Optical Access Network

Traffic trends in optical access networks have been shifted from web based services to video and multimedia services. There is a huge gap and mismatch between current trends and existing fixed network infrastructure, which intensely demands the need of next generation optical networking. For next generation optical access networks, wavelength division multiplexed passive optical network (WDM-PON) is a promising broadband optical access solution. WDM-PON is renowned as a favorable next generation access network due to provision of high bandwidth and low cost of maintenance. Due to its capability for future-proof demands WDM networks depends on highly efficient, large capacity networks as well as the practical and economical photonic/electronic devices. The simple and cost effective optical line terminal (OLT)arrangements are specially desired for WDM-PON. In this dissertation, new cost effective optical frequency comb generators with different number of comb lines in cascade mode is proposed which supports high capacity networks based on WDM-PON. The proposed optical frequency combs (OFCs) have been deployed at optical line terminal side of WDM-PON architectures by replacing number of laser arrays. All the proposed combs have high tone to noise ratio with least power spectral difference. Different modulation techniques are implemented for transmitting the data via each comb line of the proposed setups. After deploying the generated comb lines in WDM-PON setups, high capacity networks of 40 Gbps, 400 Gbps, and 1.2 Tbps have been achieved.Various modulation techniques are deployed along the OFCs that supports different number of bits per symbol. All the techniques presented theoretically which have been verified with simulation results, whereby the results are in good agreement with the theoretical analysis. Furthermore,transmission impairments due to Rayleigh backscattering (RB) in a cost effective single feeder fiber is a challenging phenomenon which degrades the transmission performance. In this thesis, a new scheme is presented which minimized the effect of RB to the minimum extent. The main work and innovative contributions are listed as followes.1?A cost effective OLT arrangement based on OMC is proposed. This scheme can realize full duplex 40 Gbps DPSK transmission. Numeral results show that it can provided enough system margin with high splitting ratio at 1:64 and minimum power penalties.2?A very cost effective OLT arrangement is proposed based on cascaded connection of three modulators with single laser source which provided high number of frequency tones (40) in such a configuration,each carrier supported 10 Gbps DPSK based modulated data, it supported 400 Gbps full duplex based on WDM-PON transmission with adequate power.3?Another OMC is proposed which is based on a pulsed laser based source connected in cascaded with the modulators, it provided the maximum number of frequency tones (60), yet with simple structure. Furthermore, each frequency could transmit 20 Gbps data based on DQPSK based transmission, in total providing 1.2 Tbps data transmission in WDM-PON.4?A new model for mitigating RB noise is proposed. It uses dual drive MZM for the generation of single side band carrier suppressed signals both at OLT and ONU side.