REALIZATION OF WAVELENGTH CONVERSION AND DENSEWAVELENGT DIVISON MULTIPLEXING AT 40 Gb/S

Abstract

Large bandwidth along with high transmission rate is require for today’s communication system. At present, optical fiber is the only medium for it with low loss communication links. With growing transmission rates, electronic regeneration become more and more expensive. So to overcome this problem of elctronic regenration, switching to optical domain is the best way to cater the high speed processing demand of the user. This can be accomplished by use of optical amplifier which are bit transparent and have an ability to amplify the signals at different wavelength simultaneously. These properties of optical amplifier are used to carry out the parallel logic and arithmetic operation which can remove the large power consumption and complexity of elctro-optic conversion. Semiconductor optical amplifier is one of the optical amplifier which is most suitable for high speed communication because of its distinct inherent characteristics like insensitivity to input signal modulation characteristics, polarization independent property, high saturation output power, low nonlinearties etc. So high speed optical processing need was felt to cater the ever increasing high speed demand of the user in the high speed traffic network. The work was done for wavelength conversion by using nonlinear properties of semiconductor optical amplifier, the cross phase modulation (XPM), four wave mixing (FWM) its at rate of 20Gb/s but the work done could not be done beyond 20Gb/s with high conversion efficiency because of their nonlinear behaviour due to insensitiveness of polarization property. In the present work, the cross gain modulation (XGM),another nonlinear properties of semiconductor optical amplifier is used to convert the 1550 nm wavelength to 1549nmwavelength signal because of its high conversion efficiency and polarization independent property. In this thesis, the wavelength conversion has been done by using XGM at a rate of 40Gb/s by choosing the optimum value of .6ns carrier lifetime and 40mA current biasing where the nonlinearty are less and power content of signal is high i.e. 26dbm in the parametric range of [193.102-193.728THz] further, in the thesis, cross gain modulation (XGM ) is used to realize the dense wavelength division multiplexing (DWDM) system at a rate of 40Gb/s with same carrier life time and current biasing parameter.