Power consumption analysis of an optical modulator based on different amounts of graphene

Abstract

Energy-efficient devices will play a key role in the continued performance scaling of next-generation information and communications technology systems. Graphene has emerged as a key optoelectronic material with unique energy-like properties. But to the best of our knowledge, these advantages have not yet been fully exploited in optical modulators design. In this work, we design and analyze an optical modulator which is composed of two graphene layers and a ring resonator made with different amount of graphene. For performance analysis, the ring resonator’s amount of graphene is varied from 25 to 100% with four discrete steps. The critical coupling condition representing the OFF-state, and the 3-dB transmission level representing the ON-state of the device are obtained. Numerical results show this new optical modulator consumes as little energy as 4.6 fJ/bit whilst achieving a high-speed operation with a bandwidth up to 42.6 GHz when employing surprisingly only 25% of graphene. The 42.6 GHz modulator has a footprint as small as 22.1 µm2 with an active area of 1.68 µm2 only, the smallest active area to date. Alternatively, the optical modulator achieves up to ∼88.5 GHz at the expense of consuming 17.5 fJ/bit when using 100% of graphene. The proposed graphene-based modulator proved to be a compact, energy-efficient, high-speed device, useful for a myriad of applications including mobile fronthaul, telecom, and datacom.