The invention provides a device and a method for tuning echo wall micro-cavities. The device comprises an
optical fiber. The echo wall micro-cavities which are positioned on a side of a
fiber core are arranged in cladding of the
optical fiber,
graphene is laid at cavity openings of the echo wall micro-cavities and is connected with electrodes, and voltages are applied to the
graphene by the electrodes, so that the echo wall micro-cavities can be tuned. The device and the method have the advantages that the echo wall micro-cavities are integrated in the
optical fiber, the
fiber core in the optical
fiber is used as
waveguide for exciting the echo wall micro-cavities, and accordingly the device is compact and stable in structure; distances between the echo wall micro-cavities and the
waveguide for exciting the echo wall micro-cavities rarely change in tuning procedures, accordingly, the device and the method rarely affect quality factors of the echo wall micro-cavities, and the tuning accuracy of the echo wall micro-cavities can be improved; only input
laser devices are required in the tuning procedures, extra
laser devices can be omitted, and accordingly the device and the method are low in tuning cost; the
graphene is extremely high in heat
conductivity, heat generated by the graphene can be quickly transmitted to the echo wall micro-cavities, and accordingly the device and the method are high in tuning efficiency.