Highly Sensitive All-Optical Control Of Light In Ws2 Coated Microfiber Knot Resonator

All-optical light-control-light functionality is realized in a layered tungsten disulfide (WS2) nanosheet coated microfiber knot resonator (MKR) structure. Mainly due to the photon generated excitons induced refractive index variation in WS2 nanosheets, a large variation in the transmitted power (Delta T) can be observed under external violet/red laser excitation. The Delta T variation rates can reach up to similar to 0.4 dB/mW under violet pump light excitation whereas the state of the art light-control-light structures usually has a variation rate of less than 0.25 dB/mW. In terms of the response time, the averaged rise/fall time is similar to 0.12/0.1 s. The demonstrated structure has the advantages of easy fabrication, low cost and high sensitivity, therefore, it might be a promising candidate for building future all-fiber-optics based functional devices and all-optical circuitry. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement