Energy-efficient tunable silicon photonic micro-resonator with graphene transparent nano-heaters

TL;DR

This paper introduces a graphene-based transparent nano-heater for silicon micro-resonators, offering improved efficiency, response time, and integration potential for photonic circuits compared to traditional metal heaters.

Contribution

The paper presents the first experimental demonstration of graphene nano-heaters directly contacting silicon micro-cavities, enhancing thermal tuning performance in photonic devices.

Findings

Graphene nano-heaters improve heating efficiency and response time.

Direct contact with silicon enhances thermal tuning performance.

Potential applications in optical modulation and switching.

Abstract

Thermally-tuning silicon micro-cavities are versatile and beneficial elements in low-cost large-scale photonic integrated circuits (PICs). Traditional metal heaters used for thermal tuning in silicon micro-cavities usually need a thick SiO2 upper-cladding layer, which will introduce some disadvantages including low response speed, low heating efficiency, low achievable temperature and complicated fabrication processes. In this paper, we propose and experimentally demonstrate thermally-tuning silicon micro-disk resonators by introducing graphene transparent nano-heaters, which contacts the silicon core directly without any isolator layer. This makes the graphene transparent nano-heater potentially to have excellent performances in terms of the heating efficiency, the temporal response and the achievable temperature. It is also shown that the graphene nano-heater is convenient to be used in ultrasmall photonic integrated devices due to the single-atom thickness and excellent flexibility of graphene. Both experiments and simulations imply that the present graphene transparent nano-heater is promising for thermally-tuning nanophotonic integrated devices for e.g. optical modulating, optical filtering/switching, etc.