▎ 摘　　要

NOVELTY - Preparing coated optical fiber comprises putting graphene dispersion liquid into centrifugal tube, collecting graphene nano sheet in graphene dispersion liquid at bottom of centrifugal tube through centrifugal action of centrifuge, and extracting from bottom of centrifugal tube to obtain graphene nano-sheet dispersion liquid, washing optical fiber with acetone to remove pollutant on surface, soaking optical fiber in sodium hydroxide solution and standing for 1 hour, taking out optical fiber, and using deionized water and ethanol to wash residual sodium hydroxide solution on surface of optical fiber, soaking optical fiber in 3-aminopropyl triethoxysilane solution to finish silanization treatment to form amino, putting optical fiber into prepared sample groove. USE - Method for preparing a coated optical fiber that is utilized in a refractive index detection device (claimed) and in optical fiber sensing. ADVANTAGE - The method enables preparing the coated optical fiber in a simple and inexpensive manner with high sensitivity of the refractive index detection device. DETAILED DESCRIPTION - Preparing coated optical fiber comprises putting graphene dispersion liquid into centrifugal tube, collecting graphene nano sheet in graphene dispersion liquid at bottom of centrifugal tube through centrifugal action of centrifuge, and extracting from bottom of centrifugal tube to obtain graphene nano-sheet dispersion liquid, washing optical fiber with acetone to remove pollutant on surface, soaking optical fiber in sodium hydroxide solution and standing for 1 hour, taking out optical fiber, and using deionized water and ethanol to wash residual sodium hydroxide solution on surface of optical fiber, soaking optical fiber in 3-aminopropyl triethoxysilane solution to finish silanization treatment to form amino, putting optical fiber into prepared sample groove, adding graphene nano-sheet dispersion, and forming graphene film on surface of optical fiber, putting prepared optical fiber with graphene film on surface in vacuum drying box for annealing treatment to prepare graphene film on surface of optical fiber, and preparing multi-layer graphene film on surface of optical fiber to obtain coated optical fiber.