Four-Wave Mixing in a Microfiber Attached Onto a Graphene Film

We demonstrate effective four-wave mixing in a 2- \mu{\rm m} microfiber attached onto a graphene film by using two continuous-wave pump lasers at wavelengths near 1550 nm. With a contact length of 10 mm between the microfiber and the graphene film and input powers of 600 and 100 mW for the two pumps, we achieve a conversion efficiency that varies from {-}{28} to {-}{\rm 34}~{\rm dB} as the wavelength difference between the two pump lasers varies from 0.5 to 4.5 nm. Graphene-attached microfibers could find applications as miniaturized nonlinear devices in optical signal processing.