Gate‐Tunable Graphene Optical Modulator on Fiber Tip: Design and Demonstration

Abstract A fiber‐end‐face‐integrated electrically tunable optical modulator based on graphene field‐effect transistor and the fabrication technique are proposed and demonstrated. The all‐fiber device features a scheme of compactness and high integration when applied to fiber optical system, as well as a low insertion loss since spatial coupling of light is avoided. A reflecting structure is used and the electro‐optic modulator shows vivid modulation when gate voltage gets tuned, with maximum optical reflectance modulation depth over 1% in demonstration. To the best of the authors’ knowledge, it is the first time to build an all‐solid gate‐control modulator directly on fiber facet. The fabrication methods introduce workflows of silicon‐on‐insulator processing into the optical fiber end‐face micromachining domain which can be applied to more comprehensive configurations, broadening the path of fiber‐end‐face integrated device.