| Tungsten disulfide(WS2)is a typical graphene-like transition metal sulfide with stable structure,large specific surface area,high carrier mobility,and electrical and optical properties related to the number of layers.In the field of sensing and all-optical device design,it shows great potential for development.Optical fiber Mach-Zehnder(M-Z:Mach-Zehnder)interferometer has the advantages of small size,simple structure,high sensitivity and good integration,etc.It is widely used in the field of optical fiber sensing.Therefore,using the excellent characteristics of WS2,combined with the excellent performance of optical fiber M-Z interferometer,to construct a new type of WS2 film optical fiber M-Z interferometer and study its characteristics,the development of sensing technology,the development of optical devices and the construction of all-optical network have very important significance.This paper takes the WS2 film fiber M-Z interferometer as the research object,based on the unique electrical and optical characteristics of WS2,through the combination of theory and experiment,the gas sensing and light regulation characteristics of the WS2 film fiber M-Z interferometer are studied.The main work of the paper includes:1.Summarize the research status of WS2 in gas sensing and light regulation characteristics and the development status of the combination of WS2 and optical fiber devices.2.Theoretical analysis of the optical fiber M-Z interferometer refractive index sensing principle,the internal light field of the structure,the output interference spectrum and the spatial frequency were simulated,and combined with the sensing principle for analysis.The relationship between the thickness of the sensing fiber cladding and the working mode was explored,and the effects of different core-diameter ratios on the mode field distribution were studied.3.Research on NH3 sensing characteristics of WS2 film fiber M-Z interferometer.The NH3 sensing performance of WS2 film fiber M-Z interferometer with different thickness was tested.The experimental results show that when the thickness of the WS2 film is 1.1?m,the interferometer has good sensing performance.The sensitivity is 2.21pm/ppm in the range of 0-100ppm ammonia gas concentration,and the sensitivity after decladding treatment is 3.35pm/ppm,response and recovery time are 30s and 240s respectively.4.Study on the optical power control characteristics of WS2 film fiber M-Z interferometer.By changing the size of the incident optical power,the relationship between the WS2 film with different thickness and the incident optical power is explored.The experimental results show that the 1.5?m thick WS2 film fiber M-Z interferometer has higher modulation efficiency.During the process of increasing the output power of the broadband light source from 4.12mW to 12.86mW,the output spectrum drifts by 0.64nm to the short wave direction,and the wavelength sensitivity is 59.6pm/ppm.5.Study on the polarization control characteristics of WS2 film fiber M-Z interferometer.The principle of polarized light regulation of WS2 film fiber M-Z interferometer is theoretically analyzed and verified by experiments.The experimental results show that when the angle of the incident polarized light changes from 0°to 180°,the center wavelength of the interference trough near 1548nm drifts by 0.71nm to the long wave direction,and at three polarization angles of 45°,90° and 135°,the spectrum The amount of drift is significantly increased. |
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