High-Contrast Electrooptic Modulation of a Photonic Crystal Nanocavity by Electrical Gating of Graphene
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- 作者：Xuetao Gan ; Ren-Jye Shiue ; Yuanda Gao ; Kin Fai Mak ; Xinwen Yao ; Luozhou Li ; Attila Szep ; Dennis Walker ; Jr. ; James Hone ; Tony F. Heinz ; Dirk Englund
- 刊名：Nano Letters
- 出版年：2013
- 出版时间：February 13, 2013
- 年：2013
- 卷：13
- 期：2
- 页码：691-696
- 全文大小：346K
- 年卷期：v.13,no.2(February 13, 2013)
- ISSN：1530-6992
文摘
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鈥檚 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.