ABSTRACT
Optical technology is poised to revolutionize short-reach interconnects. Integrated optical modulators with high bandwidth, small footprint, and broadband optical spectrum are a critical part of optical circuits. Graphene has attracted growing attention due to its excellent optical and electrical properties since its discovery in 2004. Besides, Al2O3, which deteriorates the mobility of graphene, is replaced by hBN with a low permitivity so that RC constant reduces significantly. Consequently, modulation depth and speed improve dramatically. The operation principle is as follows: We can modulate the absorption coefficient of graphene by altering its Fermi level with voltage applied to the double-layer graphene separated by Al2O3. Until now, much progress has been made in graphene-based optical modulators, but it does not match optical interconnects so well, which need high bandwidth, large modulation depth, and low insertion loss, because of some shortcomings.
