Study On Optical Parameter Amplifier And Wavelength Conversion Based On Photonic Crystal Fiber

Recently, high-nonlinear-fiber-based Optical Parameter Amplifier (FOPA) got the widespread concern. FOPA can provide high parameter gain and low noise figures by highly efficient Four Wave Mixing (FWM). On the other hand, parametric gain may be exploited as a tunable gain mechanism in wavelength conversion which has an important application in Wavelength Division Multiplexing (WDM) system. Using conventional fibers as parametric medium, the drawback is that the parametric gain is generally narrowband and it is only obtained in the anomalous dispersion regime. Due to that high nonlinear Photonic Crystal Fiber (PCF) possesses excellent flattened-dispersion with controlled zero-dispersion wavelength, parameter amplification based on PCF can obtain high gain and tunable wavelength conversion over a wide wavelength range whenever the fiber dispersion at the pump wavelength is negative or positive. Furthermore, shorter length of PCF can help to reduce the total fiber loss and minimize the influence of SRS on the parametric effects.This dissertation focuses on the PCF-based FOPA and wavelength conversion technology in optical communications, which is described as follows:In Chapter one, summarizes the research and major progress achieved in the fiber optical parameter amplification and wavelength conversion by theory, and demonstrates its potential application. Pointed out the advantages and the feasibilities of choosing PCF as a enlarge medium.In Chapter two, introduces several different type of PCF,the basic principles of optical guide and some excellent characteristics, finally analyses its potential applications in optical communications. PCF has three outstanding advantages: single-mode transmission characteristics,the highly nonlinear dispersion effects, and controllable dispersive properties. Based on above analysis, discusses the application of PCF in active devices, and some other fields else.In Chapter three, starts with a brief introduction of the FOPA and wavelength conversion theory. Then establishes a theoretical model, and analyses the FOPA characteristics of gain,sensitivity,and bandwidth, as well as conversion efficiency,conversion bandwidth of the wavelength converter by solving its nonlinear coupled wave equations. Identify the key performance parameters. From analysis, we can see that in order to achieve single-pumped FOPA's high gain and wide bandwidth, high power pump,high nonlinear coefficient,short fiber length,pump wavelength close to zero dispersion wavelength and low dispersion slope are needed.In Chapter four, based on the analysis of key technology in actual process, the experiment is designed and carried out. The experimental results show that parametric amplification and wavelength conversion can be achieved by 40m-long flattened-dispersion PCF. When pump wavelength of 1552 nm, power before coupled with signal of 22 dBm, the signal net-gain is 3 dB, maximum wavelength conversion efficiency is about -26 dB and the conversion bandwidth is 28 nm.