An all-fiber optical temporal differentiator for wavelength-division-multiplexed system based on twin-core fiber

A multichannel optical temporal differentiator implemented based on twin-core fiber for wavelength-division-multiplexed (WDM) system is proposed. The key feature of the proposed temporal differentiator is that WDM signals at nominal central frequencies can be simultaneously processed. As an example, a 16-channel WDM first-order optical temporal differentiator is designed and numerically proved, the central frequencies are located at the nominal central frequencies which are suggested in IUT-T G.692 recommendation. The designed device is practically feasible and offer the operation bandwidth of 33.5 GHz and the channel spacing of 100 GHz. Furthermore, the channel numbers can be easily expand to 32, 64, even 128. Performance analysis results show a good accuracy calculating the first-order time differentiation of the standard WDM signals centered at the nominal central frequencies with high energetic efficiency.