Microfiber-integrated Reduced Graphene Oxide Sheet And Its Control Characteristic Of Pump Light

Recently, graphene and alternative materials of graphene combined with micro-nano scale optical waveguide photonic devices become one of the hotpots.A new material with single carbon atoms thick(graphene) is consisted of a two-dimensional honeycomb structure with sp2 hybrid connection, showing its charming properties such as the superior electron transfer ability and excellent optical/electrical characteristics, which possesses great potential application in high-performance composite materials, optical communications, photoelectric detections and so on. However, graphene is difficult to induce a reaction with other media due to its complete structure and stable chemical properties so as to have low solubility in water or other organic solvents. This makes it complex to product the optical devices based on graphene, limiting the further research of graphene.The process for the preparation of reduced graphene oxide(r GO) belongs to chemical stripping method, another form of graphene, through reducing graphene oxide(GO) using strong reductant. Its lattice defects within the site can provide active site for chemical functional groups. As the most common alternative materials, rGO not only inherits the extraordinary features of graphene, also has some advantages like a simple synthesis method and the large scale preparation of production, which is widely used in research.The diameter of optical fiber reached micron-sized intitules microfiber(MF) and its length can reach centimeter. MF has become the construction of new micro-nano optical system basic components because of its remarkable optical properties including the manageable evanescent field, limiting the light in subwavelength scale and long distance transmission with low loss, etc.To investigate the response characteristics of the optical transmitted power(λ=1550nm) of the MF and broadband(1520-1620nm), violet light(λ=450nm) as pump source is employed to illuminate the rGO sheet. The experimental results show that the bare MF in response to the pump power variation is maximized ~0.07 dB. When the pump power increases from 0mW to 12 mW, the maximum change of the optical transmitted power for the MF integrated rGO sheet is ~1.6dB with the linear correlation coefficient(LCC) of ~95.7%, while the response is ~1.37 dB when the pump power decreases from 12 mW to 0mW with the LCC of ~88.7%.Experimental results indicate when the violet light power changes from 0mW to 25.41 mW, the broadband spectrum of bare MF remains unchanged. The mean of optical transmitted power of broadband spectrum increases ~1.379 dB with MF deposited rGO following the external pump power rising, which has the great LLC at different wavelengths.To investigate the controllable characteristics of 980 nm wavelength, broadband(1520-1620nm) and supercontinuum, the variation of optical transmitted power for signal light is measured by using the WDM coupling 980 nm light source(as the internal pump light) and signal light source through rGO deposition MF device. The experimental results show that the bare MF in response to the pump power variation is maximized ~0.05 dB when the rate power of 980 nm laser changes from 0mW to 300 mW. While the optical transmitted power variation of MF devices deposited r GO is maximized ~5.5dB with the LCC of ~96.9%.Experimental results illustrate when the pump light power changes from 0mW to 400 mW, the broadband spectrum of bare MF remains unchanged. The mean of optical transmitted power of broadband spectrum increases ~0.621 dB with MF deposited rGO following the pump power rising, which has the great LLC at different wavelengths.Experimental results demonstrate when the pump light power changes from 0mW to 300 mW, the supercontinuum of bare MF remains unchanged. The mean of optical transmitted power of supercontinuum increases ~2.429 dB with MF deposited rGO following the pump power rising with the LCC of ~83.3%.The innovations of this paper are as follows:(1) The graphene film growth is usually used by chemical vapor deposition(CVD) method for most of devices based on graphene, then transferring graphene films through the PMMA. The evaporation deposition method used in the paper is more convenient and simple.(2) We proposes the composite waveguide structure combined MF with r GO sheet.(3) The results indicate that the light-controlled characteristics exist in the single wavelength(405nm, 980nm), broadband(1520nm-1620nm) and whole range of light, which on the basis of absorption characteristics overall light and ultrafast saturation absorption properties of r GO.(4) In addition, the optical tunability of this device is relatively facile to control with order of mW violet light and near-infrared wavelength.