title: High-contrast electrooptic modulation of a photonic crystal nanocavity by electrical gating of graphene.
abstract: We demonstrate high-contrast electro-optic modulation of a photonic crystal nanocavity integrated with an electrically gated monolayer graphene. A silicon air-slot nanocavity provides strong overlap between the resonant optical field and graphene. Tuning the Fermi energy of the graphene layer to 0.85 eV enables strong control of its optical conductivity at telecom wavelengths, which allows modulation of cavity reflection in excess of 10 dB for a swing voltage of only 1.5 V. The cavity resonance at 1570 nm is found to undergo a shift in wavelength of nearly 2 nm, together with a 3-fold increase in quality factor. These observations enable a cavity-enhanced determination of graphene's complex optical sheet conductivity at different doping levels. Our simple device demonstrates the feasibility of high-contrast, low-power, and frequency-selective electro-optic modulators in graphene-integrated silicon photonic integrated circuits.
authors: Department of Electrical Engineering, Columbia University, New York, New York 10027, USA.
authors: Xuetao
authors: X
authors: Gan
authors: Ren-Jye
authors: RJ
authors: Shiue
authors: Yuanda
authors: Y
authors: Gao
authors: Kin Fai
authors: KF
authors: Mak
authors: Xinwen
authors: X
authors: Yao
authors: Luozhou
authors: L
authors: Li
authors: Attila
authors: A
authors: Szep
authors: Dennis
authors: D
authors: Walker
authors: James
authors: J
authors: Hone
authors: Tony F
authors: TF
authors: Heinz
authors: Dirk
authors: D
authors: Englund