▎ 摘　　要

Detecting methane gas in the environment quickly and accurately is critical to preventing poisoning and leaks. This study describes a methane (CH4) gas optical fiber sensor that is coated with SnO2/graphene. The SnO2/ graphene nanocomposites were prepared by a solution-based method. An microfiber bi-taper structure is fabricated by the flame melting biconical method. And the previously manufactured SnO2/graphene methane sensitive material was then coated in the microfiber interferometer (MFI) area using the drop coating method. Methane molecules can be absorbed by the SnO2/graphene material on the fiber's surface. And it can provide the conditions for charge transfer, which leads to the change of transmission spectrum intensity. The sensing response of the sensor for methane concentration is investigated in the range of volume fraction 0-35%. The SnO2/graphene sensitive material coated fiber sensor with a low-cost and simple fabrication process provide prospects in applications widely.