Preparation And Optical Properties Of Chalcogenide Glass Microsphere Resonant Cavity

The Whispering Gallery Mode?WGM?characteristics of optical microsphere resonators have gradually become the research object of many microsphere cavity researchers,not only its high quality factor,narrow line width,but also small mode size and high energy density.The microcavity of the microsphere cavity is small in size,simple in preparation process,and easy to integrate with other devices.It has great applications in low threshold lasers,such as high sensitivity sensors and narrow band filters.The process of forming the WGM is that when the light is transmitted into the microcavity,the light will continuously reflect on the surface of the microsphere,the microcavity will control the light near the equatorial plane and will circulate along the large circumference,thus exciting the unique WGM pattern observed in the experiment.In this paper,the Tm³⁺ doped microsphere cavity based on chalcogenide glass is selected.Because of its good infrared transmittance,low phonon energy and high nonlinear coefficient,this matrix can help to add gain medium.The microspheres produce a good WGM mode.This paper focuses on the preparation and optical properties of the chalcogenide glass microsphere resonator.At the beginning of the article,describe the background of the research on the cavity of the chalcogenide glass microspheres and the research progress of the scientific research team at home and abroad.What applications of the microsphere resonators in today's society are analyzed,The research content has been specifically planned and analysized the research significance.Then,the theoretical knowledge points of the microsphere cavity are introduced in depth,and the characteristic equations and analytical solutions of the WGM mode are obtained by solving Maxwell's equations.Some optical characteristics such as the Q factor of the microsphere cavity are described by the corresponding theory.The propagation dynamics of the laser in the tapered fiber are analyzed.The three coupling cases of the microsphere cavity with the tapered fiber cone are discussed.The actual coupling provides theoretical support.The following is a detailed description of the preparation process of Ge Ga Cs I and Ge Ga Sb S as the matrix chalcogenide glass.The transmission spectrum,fluorescence spectrum,XRD pattern of the glass and the quality of the prepared microsphere cavity of the two glasses were comprehensively analyzed,comfirming the use of Ge Ga Sb S as the glass matrix is the best choice for experimental materials.Combined with the essential characteristics of chalcogenide glass and the influence of the diameter of microspheres on the characterization of microspheres,the experiment chose to use large diameter microsphere resonators for coupling experiments.Based on the preparation technology of the original microspheres,the equipment and preparation method were improved to obtain the large-diameter microsphere resonator required for the experiment.The conditions and preparation process of the preparation of the tapered fiber were introduced,describe specific operations in the fiber cone coupling process and some details that require attentionAt the end of the paper,a typical large diameter microsphere prepared from Tm³⁺ doped Ge Ga Sb S chalcogenide glass can easily obtain the Whispering Gallery Mode?WGM?mode in the 1.7².0?m band,and prove that once the pump power exceeds the threshold,single-mode and multi-mode microsphere lasers can be generated.For a typical microsphere with a diameter of 258.64?m,the experimental data analysis shows that the laser threshold is 0.383 mw,the laser wavelength is 1907.38 nm,and the temperature of the microsphere cavity is changed by the heater to determine the heat of the microsphere laser.The sensitivity is 29.56pm/°C and thermal resolution of 1.69 °C.