Preparation And Properties Of Cr²⁺:ZnSe/As₂S₃:As₂Se₃ Composite Infrared Fiber Materials

2?3?m mid-infrared lasers have a wide range of applications in non-metal processing,non-destructive testing,non-invasive medical diagnostics,laser scalpels,molecular spectroscopy,remote sensing detection,infrared imaging and environmental detection.For decades,semiconductor lasers have been continuously developed and applied.Transition metal ion(TM²⁺)doped ?-? group crystal materials(ZnS,ZnSe,ZnTe,and CdSe,etc.)have attracted much attention.The representative Cr²⁺:ZnSe crystals in the family are even known as"mid-infrared titanium gem".However,with the increasing requirements for integration,portability and low cost of laser devices in the market,solid-state lasers are difficult to meet the requirements.Fiber lasers have the advantages of high integration,convenience and low cost.Therefore,researchers are eager to develop mid-infrared fiber lasers to meet market demand.Rare earth element doped chalcogenide glass has been considered as one of the best gain media for mid-infrared fiber lasers,and its special electronic layer structure brings excellent spectral properties unmatched by ordinary elements.However,the low doping concentration and quantum efficiency of rare earth ions in chalcogenide glass have limited its development in mid-infrared fiber lasers.Therefore,some researchers have begun to focus on the fiberization of Cr²⁺:ZnSe crystals.The research work is mainly divided into two methods.The first is to prepare Cr²⁺:ZnSe crystal fiber by high-pressure chemical vapor deposition.The second is to dope the Cr²⁺:ZnSe crystal with chalcogenide glass optical fiber.Based on the research concept of Cr²⁺:ZnSe-doped chalcogenide glass,this thesis will prepare composite materials in two ways and comprehensively study its feasibility.First,the thesis introduces the research progress of Cr²⁺:ZnSe crystals in mid-infrared laser and its fiberization,and puts forward the research work and significance of Cr²⁺:ZnSe crystals doped chalcogenide glass.Subsequently,the preparation of high-quality Cr²⁺:ZnSe crystals and their optical properties were studied,which laid the foundation for the preparation of high-performance composite materials.In order to match the refractive index of Cr²⁺:ZnSe crystals in the range of 2?3?m,As₂S₃:As₂Se₃ system was selected as the matrix chalcogenide glass.After adjusting the components several times,As₄₀S₅₇Se₃ was determined as matrix glass,and then low-loss matrix glass was obtained by distillation purification.Based on the concept of TM²⁺:?-? group doped chalcogenide glass proposed by S.B.Mirov et al.,Cr²⁺:ZnSe/As₄₀S₅₇Se₃ composite material was prepared by traditional melting method in the experiment,and its optical properties were characterized in detail.Aiming at the shortcomings of the traditional melting method,this paper innovatively proposes the preparation of Cr²⁺:ZnSe/As₄₀S₅₇Se₃ composite material by hot-pressing sintering method,and obtains composite materials with high transparency and strong fluorescence emission.The feasibility of hot-pressing sintering method was proved by comparative analysis with melting samples.The research work in this thesis has certain significance for the preparation of Cr²⁺:ZnSe-doped chalcogenide glass fiber materials,and provides a feasible solution for the preparation of mid-infrared active fibers.