Research On The Key Technologies Of Optical Interconnection For High Speed And Large Capacity Data Centers

Data center optical interconnection is an important business in short reach transmission optical fiber communication industry and focus.Compared with coherent optical transmission of long reach transmission system,data center interconnection as a representative of short reach transmission system,considers the cost,power consumption and the complexity of the problem,which more tend to be low cost and high rate of optical fiber transmission system.In this thesis,the application background is optical interconnection between data centers.The research content is divided into two parts.The first part studies the optical field recovery technology of the single polarization direct detection system.The second part studies the polarization demultiplexing technology of the polarization multiplexing direct detection system.The system structure,transmission efficiency,signal and signal beat interference(SSBI)elimination,cost control and other issues are studied.New or improved transmission system scheme and DSP algorithm are proposed,which improve the transmission effectiveness and reliability of short-reach optical interconnection system.The main research work of this thesis is as follows:The first is about the single polarization direct detection system research.It mainly discusses theoretical basis and structure of system about two kinds of single-sideband signal based on Kramers-Kronig detection(SSB-KK)systems and four kinds of twin single-sideband signal based on carrier assisted differential detection(Twin-SSB-CADD)systems.Through the theoretical derivation and simulation system,we study the performance of the systems from the carrier signal power ratio(CSPR),SSBI elimination,delay parameter,received optical power(ROP),optical signal-to-noise ratio(OSNR)and so on.The ROP sensitivity and OSNR sensitivity of SSB-KK system are higher,namely,the transmission efficiency of SSB-KK system is more advantageous under the condition of low ROP and OSNR.But its transmission efficiency is only about half of Twin-SSBCADD system,and SSBI need to be eliminated by over-sampling.Under certain condition of ROP and OSNR,the Twin-SSB-CADD system can achieve more efficient transmission.This system is a more compact and cost-effective solution,which is suitable for transmission application in data center interconnection of short reach.Secondly,the direct detection system of polarization multiplexing is studied.The receiver structure and the principle of depolarization algorithm based on Stokes space and Jones space are mainly discussed.The performance of the system is studied from the aspects of CSPR,laser linewidth,launch optical power(LOP),ROP and OSNR,which are verified by simulation system and experimental system.The ROP sensitivity and OSNR sensitivity of the polarization demultiplexing system based on Stokes space are higher,namely,the transmission is more advantageous under the condition of low ROP and OSNR.Under certain condition of ROP and OSNR,the polarization demultiplexing system based on Jones space has the advantages of simple structure,high tolerance to device performance and low cost transmission.The two different polarization demultiplexing systems have the same transmission efficiency,and each has its own advantages and disadvantages.They are suitable for the transmission application in data center interconnection of short reach under different scenarios.