The Study On All Optical Clock Recovery For All Optical 3R Regeneration

One of the two development trends in optical communication isoptical-transfer-network (OTN), even all-optical-network (AOC) with high speed andlong haul. The optical signals will be degraded by many factors, which limit thetransmission capacity and distance. This problem can be well solved by usingall-optical 3R regeneration. Clock recovery is a key technology in all-optical 3Rregeneration. In this paper, we spread our work on injection mode-locked clockextraction in following aspects.1. As the key component of clock recovery, SOA is studied theoretically in detail.The characteristics of SOA-XGM are emulated using software Optisystem3.0.Then we complete the experiment of 40Gbps wavelength conversion, from whichwe validate the simulation results. So that we make the theoretical andexperimental foundations on using SOA effectively in clock recovery.2. Base on the analysis of active mode-locked fiber laser, we demonstrate theprinciple of injection mode-locked fiber laser. We also introduce the basicstructure and principle of the Mach-Zehnder interferometer (MZI), and investigateits transmission functions both in time domain and frequency domain. Thesesupport the injection mode-locked clock recovery in theory.3. We carry out the experiments of all-optical clock recovery based on injectionmode-locked laser. At first, we complete 10Gbps clock extraction and get thewaveform and spectrum figures with good characteristics, from which the effectof MZI be proved. Then we successfully extract 40Hz clock pulses from 40Gbpspseudo-random signals. Changing the injection signal power, the bias current ofthe SOA and the central wavelength of the filter, and we get the differentexperimental effects of the clock signals.4. We perform the clock extraction experiments utilizing an ultrafast nonlinearinterferometer (UNI). First, We introduce the basic work principle of the UNIthrough the analysis of the Jones Matrix and the transmission function. Then wedemonstrate the clock recovery scheme using the UNI, and achieve the10Gbps/40Gbps clock recovery. At the same time, we observe the different clockwaveforms under the different conditions, such as the control signal power, thebias current of the SOA and the work current of the EDFA.