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Research On The Optical Buffer Based On Nonlinear Polarization Rotation In SOA And Its Cascade

Posted on:2010-10-09Degree:DoctorType:Dissertation
Country:ChinaCandidate:M ChengFull Text:PDF
GTID:1118360275463232Subject:Optics
Abstract/Summary:PDF Full Text Request
Optical packet switching networks are transparent to the data rate,modulation format,transmission protocol,and so on.Therefore,the optical packet switching(OPS) emerge as first scheme for the next generation switching systems,which accommodate huge data-centric traffic at the packet level granularity and match the high transmission capacity provided by the dense wavelength division multiplexing(DWDM) technologies.OPS are the key approach to build future compact and power-efficient all-optical data routers with greater scalability,flexibility,and switching capacity.One of the most critical components in such an all-optical router is the optical buffer,which stores the data packets for a desired amount of time during destined output switch fabric port contention and releases the data packets while the destined output port is cleared. Optical buffer can also be use in optical packet synchronization and traffic shaping.In the dissertation,we proposed a novel optical buffer based on the nonlinear polarization rotation in SOA,which is cost-effective,compact and low power consumption,and can provide variable buffer length,fast dynamic reconfiguration in picoseconds.These conclusions can also be applicable for all the other SOA based optical buffers.What I have done during the PHD period are as follows:For the first time we have presented a simple principal states of polarizations (PSP) model that is capable of describing the behavior of polarization switches based on nonlinear polarization rotation in SOA with tail fibre.Using this theory we experimentally study the nonlinear polarization switching based on the polarization rotation in SOA.During the experiment,the output SOP evolution in SOA can easily be tracked and controlled on line.We have also demonstrated a nonlinear polarization switching based on the polarization rotation induced by bias current in SOA. Experimental results show that the static contrast ratio is more than 20dB and the dynamic contrast ratio is more than 10dB.We present a novel optical buffer based on nonlinear polarization rotation induced by inject current of SOA.This buffer is simple,compact,cost effective,low power consumption and easy to cascade.With the buffer configuration,the signal can pass directly if the signal does not need buffer.In addition,the buffer depth can exceed 50% and the configuration is easy to cascade.With the novel design,we had successfully demonstrated the loading and reading operation at bit rate of 2.5 Gb/s.Random data of 1024-bit was buffered for 12 circulations(11μs).We present the cascaded buffer scheme without space switching to achieve variable-length delay buffer.The most interesting features of this new buffer are that it has more than 1000 optional delay lengths,fast dynamic reconfiguration in picoseconds. With two stages cascaded buffer,we had successfully demonstrated 60 buffering times at 2.5 Gb/s,the maximum buffer time is~40μs.With three stages cascaded buffer,we had successfully demonstrated 144 buffering times at 2.5 Gb/s,the maximum buffer time is~50μs.
Keywords/Search Tags:All-optical packet switching, optical buffer, Semiconductor optical amplifier, Nonliear polarization rotation
PDF Full Text Request
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