Characteristic Of Slow Light And Parametric Oscillator Based On Fiber-optic Parametric Amplification

With the rapid development of information technology,the transmission capacity and bandwidth was increasing dramatically.Consequently,the current bandwidth resources can't meet the requirements of people.Therefore,it is necessary to explore a novel dense wavelength division multiplexing all-optical transmission system with high-speed,high-capacity,long-distance and high spectral efficiency.Especially,a new type of multi-wavelength laser,all-optical buffering and all-optical switching has become a hot issue and subjected enormous challenges in all optical communication.Recently,the process of fiber optical parametric amplification(FOPA)has attracted considerable attention because of their potential applications in modern fiber-optic communication systems due to its remarkable features,such as high gain,large gain bandwidth,arbitrary waveband operation,ultra-fast response,multi-channel signal amplification and so on.In this thesis,we theoretically and experimentally study the application of the FOPA in all-optical network:the characteristics of slow-light delay line based on FOPA process and the fiber-optic parametric oscillator(FOPO).The theoretical and experimental results show that FOPA has potential to realize controllable optical memory and to obtain pulse trains,which can be used in fixture optical buffers and all-optical information processing systems.The main contents include the following parts:firstly,we derived the analytical solution of the signal delay with small-signal gain,and investigated the delay characteristics of the gain spectrum.Then,a multi-wavelength FOPO based on multiple four-wave mixing(multi-FWM)processes is presented.Ultimately,we proposed and experimentally demonstrated a photonic method to generate pulse trains with doubled repetition rate in FM actively mode-locked FOPO.The main achievements are listed below:Firstly,we proposed and experimentally demonstrated a slow light system based on the process of FOPA.Additionally,we analyzed the factors which will influence the signal delay,such as pump power,dispersion,nonlinear coefficient,etc.Then,the result of lOGbit/s Pseudo-Random Binary Sequence pulse signal delay is demonstrated through experimental demonstration with a low pump power(<1W),which can verify the feasibility of the tunable optical delay line based on FOPA.Secondly,a multi-wavelength FOPO based on multi-FWM processes is investigated numerically and demonstrated experimentally.The theoretical model of FOPO based on the multi-FWM processes is presented.It is proved that the output signal starts to saturate while the high-order parametric products have been generated in the multi-FWM processes of FOPOs.Moreover,higher output power of idler(i.e.,the first-order parametric produce)is achieved.On the other hand,the level of pump power is proved to be a key factor that significantly influences the output of the FOPO,which promotes the application of FOPO-based multi-wavelength laser field.Finally,a photonic method to generate pulse trains with doubled repetition rate has been proposed and experimentally demonstrated in FM actively mode-locked FOPO.We experimentally demonstrated the characteristics of the FM actively mode-locked FOPO,and analyzed the effects of the pump power and modulation frequency on the features of the generated pulses(e.g.,output power,RMS timing jitter,pulse width and time-bandwidth product).Experimentally,a stable pulse trains of 37ps with a RMS timing jitter of around 2.51ps and a repetition rate of 10GHz are generated.The corresponding TBW product is about 0.63.In addition,the state of FM actively mode-locked FOPO can be controlled by the polarization state of light.We can obtain two optical pulse trains corresponding to two different mode-locked states by rotating the intra-cavity polarization controller.In the experiment,8,10,12 and 14GHz pulse trains are generated using RF drive frequencies of around 4,5,6 and 7GHz,respectively.In summary,this thesis focused on the characteristics of slow-light delay line based on FOPA process and the generation of FOPO.A slow light system based on the process of FOPA is proposed,which has the potential application in FOPA-based optical signal buffering field.Furthermore,we presented a multi-wavelength FOPO based on multi-FWM.Meanwhile,a new photonic method to generate pulse trains with doubled repetition rate in FM actively mode-locked FOPO has been proposed and experimentally demonstrated.These can be used in the applications of FOPO-based multi-wavelength lasers and pulse trains generators.