Enhancing the Capability of A Hybrid TWDM/PON Using Waveguide-Integrated Si/2D Material-Based Photodetector with the Most Suitable Metal-2D Material-Metal (M-2DM-M) Configuration

In the proposed work, a novel architecture of a 10-channel hybrid time-wavelength division multiplexing/passive optical network (TWDM/PON) system is investigated for different data rates: low data rate (2.5 Gbps) and high data rate (10 Gbps) using different two-dimensional (2D) material-based photodetectors with a metal-2D material-metal (M-2DM-M) device structure. Integration with Silicon (Si) semiconductor makes the detectors highly compatible with complementary-metal-oxide-semiconductor (CMOS) technology. The performance of the system is measured in terms of eye diagrams obtained using OptSim Software. Graphene, transition metal dichalcogenides (TMDCs), and black phosphorus (BP) are the three materials used to enhance performance metrics of high-speed optical networks. Results reveal that, among the three materials, BP provides the best performance for a low-data-rate optical network at 2.5 Gbps with a high Quality factor (Q-factor) of 32 dB and low Bit error rate (BER) of 1 x 10-40. Whereas the worst results with a low Q-factor of 13.24 dB and high BER of 2.26 x 10-6 are attained by metal-TMDC-metal (M-TMDC-M) over the same length of fiber. Metal-Graphene-metal (M-G-M) gives intermediate results. For further analysis data rate is varied, and system is simulated for a high data rate at 10 Gbps over 10 km length of fiber. It is found that, for a high data rate, metal-graphene-metal (M-G-M) gives best result among others, with a maximum Q-factor of 28 dB and low Bit error rate (BER) of 1 x 10-38 is achieved using metal-graphene-metal (M-G-M) over 10 km length of fiber. Whereas the worst results with a low Q-factor of 12 dB and high BER of 5.46 x 10-5 are attained by metal-TMDC-metal (M-TMDC-M) over the same length of fiber. A metal-black phosphorus-metal (M-BP-M) photodetector yields intermediate results in a high-data-rate optical network. Jitter value and eye closure are other performance metrics obtained from eye diagram. It shows that the performance of system for low data rate and high data rate can be enhanced by proper selection of material. M-G-M shows best performance for high data rate, and M-BP-M shows best performance for low data rate. While M-TMDC-M poorly performs in both cases, because these materials show weak absorption in telecom operating wavelengths. Hence, TMDC is not suitable for telecom wavelengths.