Efficient wavelength conversion using four wave mixing in semiconductor optical amplifier for intensity modulated differential phase shift keying signal
All-Optical Wavelength Conversion (AOWC) in Dense Wavelength Division Multiplexing (DWDM) is believed to be the next generation networks that can meet the ever increasing demand for bandwidth of the end users. Wavelength division multiplexing (WDM) has become one of the most widely utilized multiplexing techniques for transmission of optical signals. As this technique promises a larger bandwidth, high data capacity and data rates it is considered as the most efficient.
This thesis presents an efficient signal for wavelength translation in optical networks. We compared two signal i.e. non return to zero (NRZ) and intensity modulated differential phase shift keying (IM-DPSK). We performed our translation by using well known four wave mixing (FWM) technique. Our conversions try to translate the wavelengths in an efficient manner those results in very low blocking probability. We propose novel translation signal that outperform the signals reported in the literature even when converters are used.
We performed simulation in which it is proven that IM-DPSK signal which has the BER of 10-11 are more immune to non linear effects during wavelength conversion. We also performed multi stage conversion to make our conversion more flexible within a same network. Further, we analyzed the optimum point of fiber length for different power levels which is affected by BER.
Our proposed method are simple to implement and do not add to the cost. Thus, we conclude that wavelength conversion plays more significant role in affecting the blocking probability.