Preparation Of Two-dimensional Antimonene And Its Application In Near-infrared Fiber Laser

Due to their excellent physical and chemical properties,group VA graphene-like two-dimensional layered materials represented by black phosphorus have developed rapidly in the fields of materials,optoelectronic information,and energy.The new two-dimensional group VA materials are expected to be able to well complement the shortcomings of graphene and other two-dimensional materials in some aspects.In this thesis,a new type of two-dimensional layered material-antimonene was used as the research object,using different methods to prepare antimonene nanosheets and antimony films,and to characterize and analyze their basic structure.The study focused on the non-linear absorption performance of antimonene nanosheets,and integrated saturable absorption devices to realize short pulse operation in near-infrared fiber lasers.The specific content is as follows:1.The antimonene nanosheets and antimony thin films were prepared by liquid phase exfoliation and van der Waals epitaxial growth technology based on physical vapor deposition.?-phase antimonene nanosheets with an average thickness of 5-15 nm and different lateral dimensions were prepared by liquid phase exfoliation.The comparison of the Raman test results of antimony powder and antimonene nanosheets verifies the blue shift of the E_g and A_1gvibration modes of antimonene nanosheets.The antimonene nanosheets and antimony thin films were successfully grown on the fluorophlogopite substrate by physical vapor deposition.Experiments have found that Sb₄ small molecules are more suitable for van der Waals epitaxial growth of antimonene nanosheets and antimony films than Sb₂ small molecules.2.The open-aperture Z-scan was used to study the nonlinear optical absorption characteristics of the few-layer antimonene nanosheets under two different wavelengths.For the first time,the saturable absorption effect and optical limiting characteristics of?-phase antimonene nanosheets were observed simultaneously.The nonlinear absorption performance under excitation at 1064 nm wavelength is slightly better than that under excitation at 532 nm wavelength,which indicates that antimonene nanosheets are more suitable for infrared laser wavelengths.A thin-film antimonene saturable absorber was prepared,and its 11.63%modulation depth of indicated that the antimonene nanosheet saturable absorber has a strong energy bleaching ability at 1.5?m band.In addition,the saturation strength as low as 1.52 m W/cm² also shows that antimonene nanosheets are an excellent saturable absorber material.3.A passively Q-switched fiber laser with a cavity length of 9.5 m and a passively mode-locked fiber laser with a cavity length of 62 m were built using antimonene saturable absorbers.The laser pumped 445 m W is the maximum threshold for maintaining stable Q-switched modulation in the laser cavity,and the corresponding fiber laser output power is 4.5 m W.At the maximum pump energy,the highest repetition frequency and the narrowest pulse width corresponding to the Q-switched pulse are 124.1 k Hz and 1.42?s,respectively.The cavity length and polarization state were adjusted to realize the traditional soliton mode-locked laser with net total dispersion in the cavity of about-1.292 ps².Its fundamental frequency,narrowest pulse width and maximum output power are 3.285 MHz,1.349 ps and 3.69 m W,respectively.The results obtained verify the saturable absorption characteristics of antimonene nanosheets,indicating that antimonene nanosheets have a good prospect for ultrafast photonics applications in the 1.5?m band.4.A single-dual wavelength switchable harmonic mode-locked short-pulse fiber laser was built based on the antimonene saturable absorber.In the single-wavelength operation state,the first-order,second-order,third-order,fourth-order,and the highest-order 165-order harmonic mode-locked pulse output are realized respectively.The fundamental frequency is 2.16 MHz,and the center wavelength is 1564 nm.The highest order harmonic mode-locked pulse output with the same 165 order is realized under dual wavelength.The two peaks of the stable synchronous dual-wavelength output are 1561.3 and 1562.7 nm,respectively,and the difference frequency is 0.17×10¹² Hz,which belongs to the terahertz band.The results not only prove that antimonene nanosheets are a superior nonlinear optical material,but also expand the application of antimonene in near-infrared fiber lasers.