摘要
We created an all-fiber solution for fast,continuous,and controllable tuning of Fano-like resonance.By embedding a graphene-coated fiber Bragg grating into one arm of a Mach—Zehnder interferometer,the narrow Bragg resonance interacts with a broad interference spectrum,forming a sharp asymmetric Fano-like resonance line shape.With the application of an electrical voltage over the graphene layer,the generated Joule heating shifts the Bragg resonance and consequently tunes the asymmetric Fano-like resonance line shape to a symmetric dip or electromagnetically induced transparency-like peak.Further,by exploiting two modulated states with reversed Fano-like resonance line shapes,an optical switch can operate with an extinction ratio of 9 dB.The well-engineered Fano-like resonance in an all-fiber structure opens up new horizons for applications of fiber gratings in optical signal processing,slow-light lasing,and fiber sensing.
基金
National Natural Science Foundation of China(61975166,11634010,91950119)
National Key Research and Development Program of China(2017YFA0303800).
