Multiwavelength Mode-Locked Fiber Laser Based On The Tungsten Disulfide

Fiber laser is more and more important in optical communication,industrial production and biomedicine.Compared with solid laser,fiber laser has many attractive advantages,such as simple structure,low cost and easy to be miniaturization.As one of the most important types of fiber lasers,multi wavelength soliton fiber lasers have been playing an increasingly important role in many fields,such as wavelength division multiplexing,optical detection and optical sensing.Multi wavelength soliton fiber laser is the ideal light source for long distance and large capacity optical fiber communication system.In order to achieve the multi wavelength soliton output of optical fiber laser,two kinds of active mode locking and passive mode locking are mainly methods.Compared to the active mode-locked usually required acoustic optical or electro-optical modulator,passive mode locking has many advantages,the advantages of more simple structure,the output pulse width is more stable to passively mode-locked mode to achieve multi wavelength mode-locked with more extensive research and application.As one of the key devices in passive mode locked soliton fiber laser,saturable absorber has a very important position.In recent years,with the high nonlinear refractive index,high profile depth,low saturation absorption threshold of two-dimensional materials,including topological insulators and two sulfides become the darling of the preparation of saturable absorber.At present,the research on the optical fiber lasers using two-dimensional materials is mainly focused on the single wavelength traditional soliton mode locking,and the multi wavelength fiber laser produced by the high nonlinearity is rarely studied.In this paper,a multi wavelength fiber laser is constructed by using the nonlinear and saturable absorption properties of tungsten sulfide.The formation mechanism of multi wavelength soliton fiber laser is studied.The main contents of this paper are as follows:1.Use the method of photonic deposition to prepare the tungsten carbide tapered fiber device and access it into erbium doped fiber laser,the phenomenon of multi wavelength mode-locked pulse is studied.Several kinds of soliton mode-locked pulses are obtained,such as single wavelength conventional soliton mode-locked pulse,single wavelength harmonic mode locking pulse,single wavelength noise mode locking pulse,and dual wavelength soliton mode-locked pulse.2.Design and fabricate of micro / nano fiber structure,micro and nano fiber ring,and successfully build a laser and a dual wavelength harmonic mode-locked pulse is obtained for the first time.It provides a new idea for the application of the nonlinearity of the micro / nano fiber in the passive mode locked fiber laser.3.Design and fabricate of a mode-locked device based on the tungsten sulfide and micro/nano fiber ring,and successfully achieve the output of the three wavelength harmonic mode-locked pulse.