Wang et al 8081 transferred CVD-grown graphene to a metal slot waveguide to construct an on-chip photodetector achieving a response bandwidth of 70 GHz and a responsivity of not less than 01 A·W−1 to

In the study by Wang and colleagues, chemical vapor deposition (CVD)-grown graphene was utilized to develop an on-chip photodetector by transferring it to a metal slot waveguide. The achieved outcome was a response bandwidth of 70 GHz and a minimum responsivity of 0.1 A·W−1. This advancement is of great significance as it enables the creation of a more complex polarization division multiplexing optical receiving chip and an optical coherent receiver. The schematic diagram of the proposed system is depicted in Figure 5(a)