Study On Light-control-light Characteristics Of Two-dimensional Material Tungsten Disulfide Wrapped On Microfibers

With the advancement of science and technology,high-bandwidth and low-loss fiber-optic waveguide devices are gaining more and more important status.Among them,micro-fiber(MF)devices have attracted a great deal of attention in the fields of fiber optic sensing and optical communications.The MF is fabricated by heat-flame taper drawing technique where a standard fiber is drawn into a thinned core fiber of micrometer diameter.There is a large fraction of evanescent light outside this kind of micro-fiber,therefore it provides a way of enhancing light matter interaction.On the other hand,newly discovered two-dimensional materials exhibit excellent electronic and optical properties which is a great candidate material to be combined with a MF in order to build photonic components with different functionalities.Among these two-dimensional materials,tungsten disulfide,a hexagonal semiconductor material,has high electron mobility and strong absorption characteristic in the visible regime.Consequently,it is a promising candidate in applications such as light-control-light all optic functional device.In this manuscript,the light-control-light property of a MF device coated with tungsten disulfide is investigated.The experiment is built on the p?mp-probe methods where the p?mp light frequency are varied at the wavelength of 405 nm,980 nm and 1458 nm.This light-control-light functionality is achieved via the absorption property of tungsten disulfide where the output light power will be tuned by the power of the p?mp light.A 405-nm violet laser was used to irradiate the MF tapered region coated with tungsten disulfide.The transmitted light power with respect to different p?mp light power is measured at the signal light of 1550 nm lasers and of a tunable light sources(1520 nm-1620 nm)respectively.As the p?mp power of the 405 nm laser increases from 0 mW to 17.4 mW,the MF device coated with tungsten disulfide has a transmission power change of 1.51 dB which correspond to a sensitivity of 0.088 dB/mW.On the other hand,as the p?mp power of the 405 nm laser decrease from 17.4 mW back to 0 mW,the power change is 1.45 dB which correspond to a sensitivity of 0.083dB/mW.When 1520nm-1620 nm broadband light is used as the signal light and as the optical power of the 405 nm laser increases from 0mW to 26.4mW,the maxim?m variation of the transmitted optical power over the wide band of the MF device coating with tungsten disulfide is 3.7dB.Therefore,an average sensitivity of 0.117dB/mW is obtained.In the experiment of employing 980 nm or 1458 nm as internal p?mp light signal,the output optical power variation at the signal wavelength of 1550 nm and in the range of 1520-1620 nm are both investigated.When the 1550 nm laser is used as the signal light and as the optical power of the 980 nm laser increases from 0mW to 102.3mW,the maxim?m transmitted optical power variation of the MF device coating with tungsten disulfide is 8.078 dB which corresponds to a sensitivity of 0.065dB/mW.When the 1520nm-1620 nm broadband light is used as the signal light and as the p?mp power of the 980 nm laser increases from 0mW to 184.1mW,the maxim?m variation of the transmitted light power within the wide range of the MF covering tungsten disulfide is 8.823 dB.Correspondingly,an average sensitivity of 0.042dB/mW is obtained.When the 1550 nm laser is used as the signal light and as the p?mp power of the 1458 nm laser increases from 0mW to 24 mW,the maxim?m transmitted optical power of the MF covered with tungsten disulfide is 4.03 dB which corresponds to a sensitivity of 0.169dB/mW.When 1520 nm to 1620 nm broadband light is used as signal light,the maxim?m change in transmitted light power over a wide range of MF covered with tungsten disulfide is 0.873 dB when the optical power of the 1458 nm laser increases from 6.3 mW to 37.4 mW.Correspondingly,an average sensitivity of 0.021dB/m W is obtained.In s?mmary,in the study of the light-control-light characteristics of a MF device covering with a two-dimensional material tungsten disulfide,when the 1550 nm light is used as the signal light and the p?mp light wavelength at 1458 nm,a highest sensitivity of 0.169 dB/mW is obtained.The demonstrated device has a good response in terms of light-control-light functionality.This type of structure might have potential application in the field of all-optical devices.The innovations of this paper mainly include:1.In this paper,a fiber optic device combining two-dimensional material tungsten disulfide with MF was proposed to realize the light-control-light functionality with high sensitivity.2.The optically controllable characteristics of tungsten disulfide coated MF devices in the signal light wavelength of a 1550 nm single wavelength and a broadband source(1520 nm-1620 nm)at the p?mped light wavelength of 405 nm,980 nm,and 1458 nm lasers are demonstrated.