Research Of Single Crystal Core/glass Cladding Composite Fiber For Infrared

At present,optical fiber materials are developing to infrared light band.Crystal fiber has the advantages of high temperature resistance,high thermal conductivity,high damage threshold and high nonlinear effect threshold,as well as the advantages of traditional fiber such as strong waveguide characteristics,large heat dissipation area and easy integration.Therefore,crystal fiber is regarded as the preferred material for low loss and high power conduction in mid-infrared and even far-infrared bands.This paper adopts the fiber core melting process,crystal optical fiber is natural good high temperature easy use glass material drawing performance,when the temperature rose to soften glass cladding to a certain extent and fiber core for liquid,when the melt in the glass cladding drawn under the restriction of the small and uniform diameter,length is longer and is suitable for industrialized mass production of crystal glass fiber core/cladding fiber composite material,Combined with the heat treatment technology of the crystal core/glass cladding composite fiber,it is beneficial to increase the grain size of the core,reduce the grain boundary and reduce the defect,and then to prepare the crystal fiber with high orientation.Based on the research in the composite fiber preparation technology and crystal fiber core composites fiber crystallization technology accumulation,this paper select Cs I crystal fiber core/boron silicate glass cladding fiber composite material as the research object,USES the fiber core melting of precursor fiber,prepared by the combination of electrical heating crystallization post-processing technology,improve the fiber core crystal quality.Specific research contents and results are as follows:(1)Cs I crystal core/borosilicate glass cladding composite precursor fiber was fabricated by core melting method.The thermal analysis shows that the core and cladding meet the viscosities and melting point matching.The scanning electron microscope observation shows that the core and cladding meet the high temperature wettability and thermal expansion coefficient matching.The elemental analysis shows that the Si element in the cladding glass does not obviously diffuse into the core,and the Cs and I elements in the core do not obviously diffuse into the core.X-ray diffraction analysis and Raman spectrum analysis show that the optical fiber core of the direct drawn composite precursors is polycrystalline.(2)The prepared composite precursor fiber was placed in an annealing furnace,and the heat treatment parameters were as follows: heating up to 650 ? at a rate of 5 ?/min,holding at 650 ? for 3 h,and then annealing to room temperature at 0.1 ?/h.After heat treatment,the Cs I fiber core becomes more compact,continuous and has no obvious grain boundary.X-ray diffraction analysis,Raman spectroscopy analysis,transmission electron microscopy analysis and other test results show that after heat treatment,the crystal quality of the polycrystalline Cs I fiber core composite precursor fiber is significantly improved.(3)discusses the Cs I crystal under uv and X-ray excitation of intrinsic luminescence and rare earth ions doped luminescence in fiber laser and fiber amplifier,optical functional device application prospect,explores the Cs I crystal in the visible and infrared light transmission of potential applications,for the application of Cs I crystal fiber core composite fiber laid a foundation.