Research On Dispersion-regulated Infrared Chalcogenide Fiber And Supercontinuum

The main parameters of supercontinuum light sources are bandwidth and coherence,so the work of this paper is divided into two parts:First,through the material dispersion adjustment,the dispersion zero of sulfur-based glass is reduced,which is the full-fiber of mid-infrared light sources and wide spectrum Output creates favorable conditions.Second,the waveguide dispersion adjustment is used to achieve full positive dispersion distribution and improve the spatial coherence of the output spectrum.International research on the supercontinuum output of sulfur-based fiber under the pumping of mid-infrared laser has reached a very high level.The reported step-type fibers include As₂Se₃,As₂S₃,Ge-As-Se,Ge Te-Ag I,etc.Optical Parametric Amplification(OPA)Laser Pulse Pumping.However,OPA is bulky,which is not conducive to the portability and integration of the device.Although microstructure optical fibers,such as photonic crystal fibers(PCF),can adjust the waveguide dispersion of the fiber to a certain extent,the preparation of sulfur-based PCF is too difficult.Therefore,this paper chooses material dispersion adjustment to explore the full fiber of mid-infrared light sources.The first half of this paper focuses on waveguide dispersion adjustment.The zero-dispersion wavelength of the Ge-As-Se-Te composition is red-shifted using the W-shaped refractive index profile and the double-cladding structure.Full positive distribution of the dispersion curve.The supercontinuum spectrum was simulated and experimentally output,and its coherence was simulated.It was proved that the coherence of the spectrum was greatly improved,and the effectiveness of waveguide dispersion adjustment was verified.The second half of this article mainly focuses on material dispersion adjustment,that is,introducing iodine element into a high-purity sulfur-based glass matrix to make the material's zero dispersion point blue shift.First,Ge-S-I chalcohalide glass was prepared,and the effect of iodine element on the zero-dispersion wavelength of the material was successfully verified.The possibility of sulfur halogen glass and optical fiber preparation was verified,which laid the foundation for the next preparation of high-purity sulfur halogen glass.Subsequent work proposed a new sulfur-halogen glass component,Ge-As-Se-I,which introduced the iodine element into the Ge-As-Se high-purity glass matrix and successfully made its zero dispersion point blue shift.The key water peak problem in the sulfur halogen glass was solved,and a sulfur halogen fiber with relatively low loss was successfully prepared.The fundamental mode dispersion of the fiber is calculated by simulation,and the effectiveness of the material dispersion adjustment is verified.In addition,the experimental pump outputs a wide supercontinuum spectrum,and the evolution of the spectrum is simulated and analyzed.The first chapter of this article is an introduction,which briefly introduces the mid-infrared supercontinuum,reviews the recent research status of soft glass supercontinuum,and focuses on the progress of chalcohalide infrared supercontinuum research,and presents the research of this work.The second chapter introduces the basic theory of sulfur halogen glass and supercontinuum,studies several sulfur halogen glass systems and their wave-forming regions,discusses some basic properties of sulfur halogen glass,and finds that this glass system may meet the low dispersion sulfur system.Glass requirements.The third chapter mainly introduces the realization of full positive dispersion distribution through waveguide dispersion adjustment.A well-structured double-clad Ge-As-Se-Te fiber is prepared.The loss of the fiber is tested to achieve a lower loss.The experimentally pumped supercontinuum with high coherence and simulated the coherence of the output supercontinuum.The fourth chapter mainly introduces the adjustment of the material's zero dispersion point through composition optimization,namely the preparation of large band gap and low dispersion sulfur-based glass Ge-S-I,and various performance tests,including glass preparation,fiber drawing,and thermal performance,Infrared transmission spectrum,refractive index,material dispersion curve,optical band gap and fiber loss.The fifth chapter mainly introduces the preparation of new chalcohalide glass Ge-As-Se-I and low loss and low scattered fiber,as well as various performance tests,including glass and preform preparation,fiber drawing,and infrared transmission spectral,refractive index,fiber dispersion,fiber loss,simulation and experimental output supercontinuum,and simulation and analysis of spectral evolution mechanisms.The last part is the conclusion,which summarizes the main research results obtained in this paper.