Simulated Performance Analysis of an Optical Frequency Comb in a WDM System

Abstract

This paper presents the research work for a
proposed novel scheme for generating a flat and equally spaced
optical frequency comb using a simulated layout using
Optisystem. Three pump sources at 1 nm wavelength apart are
injected along with a 25 GHz RF signal having different
amplitudes into a cascade of Dual-Drive Mach-Zehnder
Modulator and Electro-Absorption Modulator and multiple
highly nonlinear fiber loops. The initial scheme is using Four
Wave - Mixing and yields a comb of 27 lines with uneven gain
and a 6 dBm power deviation. After characterizing the response
by exploring critical parameters such as pump power, frequency
spacing, dispersion effect, Erbium Doped Fiber Amplifier and
DC bias of the modulators, the researchers were able to reduce
the power deviation down to 2 dBm at the expense of some comb
lines. This final optimized scheme was then evaluated for a
preliminary Wavelength Division Multiplexing setup having only
five channels/modes at 10 Gb/s for a channel length of 1 km.
Each of the received de-multiplexed channels was evaluated
through recorded data in the form of Bit Error Rate and Quality
factor and the final results are shown to be quite promising.