Single crystal fibers(SCF)are considered to be a combination of bulk crystals and conventional fibers,thereby possessing the stable physical and chemical properties accompanied with excellent waveguide properties.This...Single crystal fibers(SCF)are considered to be a combination of bulk crystals and conventional fibers,thereby possessing the stable physical and chemical properties accompanied with excellent waveguide properties.This paper gives a detailed introduction to the development history of single crystal fibers,including the evolution of the growth technique and the optimization of the growth process.Laser-heated pedestal growth(LHPG)and Micro-pulling-down(μ-PD)methods are considered to be the most widely used growth techniques for growing single crystal fibers,and the advantages of the two methods are also introduced in detail.The second part of this paper describes the characterization of single crystal fibers,including diameter fluctuation,crystal quality and optical losses.A series of cladding approaches for SCF,such as magnetron sputtering,sol-gel,liquid phase epitaxy,co-drawing LHPG,ion implantation and micro-structure cladding will be reviewed.In addition,the research status of single crystal fiber laser and single crystal fiber sensor are also summarized in view of the current research foundation.展开更多
We fabricate a pair of fiber Bragg gratings(FBGs)by a visible femtosecond laser phase mask scanning technique on passive large-mode-area double-cladding fibers for multi-kilowatt fiber oscillators.The bandwidth of hig...We fabricate a pair of fiber Bragg gratings(FBGs)by a visible femtosecond laser phase mask scanning technique on passive large-mode-area double-cladding fibers for multi-kilowatt fiber oscillators.The bandwidth of high-reflection(HR)and lowreflection(LR)FBG is~1.6 nm and 0.3 nm,respectively.The reflection of the HR-FBG is higher than 99%,and that of the LR-FBG is about 10%.A bidirectional pumped all-fiber oscillator is constructed using this pair of FBGs,a record output power of 5027 W located in the signal core is achieved with a slope efficiency of~82.1%,and the beam quality factor M2is measured to be~1.6 at the maximum power.The FBGs are simply fixed on a water cooling plate without a special package,and the thermal efficiency of the HR-FBG and the LR-FBG is 2.76℃/kW and 1℃/kW,respectively.Our research provides an effective solution for robust high-power all-fiber laser oscillators.展开更多
基金We gratefully acknowledge the financial support from the National key Research and Development Program of China(Grant No.2016YFB1102201,2018YFB0406502)the key Research and Development Program of Shandong province(Grant No.2018CXGC0410,2017GGX20116 and 2018JMRH0207)+1 种基金the Young Scholars Program of Shandong University(Grant No.2015WLJH36)the 111 Project 2.0(Grant No.BP2018013).
文摘Single crystal fibers(SCF)are considered to be a combination of bulk crystals and conventional fibers,thereby possessing the stable physical and chemical properties accompanied with excellent waveguide properties.This paper gives a detailed introduction to the development history of single crystal fibers,including the evolution of the growth technique and the optimization of the growth process.Laser-heated pedestal growth(LHPG)and Micro-pulling-down(μ-PD)methods are considered to be the most widely used growth techniques for growing single crystal fibers,and the advantages of the two methods are also introduced in detail.The second part of this paper describes the characterization of single crystal fibers,including diameter fluctuation,crystal quality and optical losses.A series of cladding approaches for SCF,such as magnetron sputtering,sol-gel,liquid phase epitaxy,co-drawing LHPG,ion implantation and micro-structure cladding will be reviewed.In addition,the research status of single crystal fiber laser and single crystal fiber sensor are also summarized in view of the current research foundation.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.11974427 and 12004431)State Key Laboratory of Pulsed Power Laser(Nos.SKL-2020ZR05 and SKL2021ZR01)Postgraduate Scientific Research Innovation Project of Hunan Province(No.CX20200046)。
文摘We fabricate a pair of fiber Bragg gratings(FBGs)by a visible femtosecond laser phase mask scanning technique on passive large-mode-area double-cladding fibers for multi-kilowatt fiber oscillators.The bandwidth of high-reflection(HR)and lowreflection(LR)FBG is~1.6 nm and 0.3 nm,respectively.The reflection of the HR-FBG is higher than 99%,and that of the LR-FBG is about 10%.A bidirectional pumped all-fiber oscillator is constructed using this pair of FBGs,a record output power of 5027 W located in the signal core is achieved with a slope efficiency of~82.1%,and the beam quality factor M2is measured to be~1.6 at the maximum power.The FBGs are simply fixed on a water cooling plate without a special package,and the thermal efficiency of the HR-FBG and the LR-FBG is 2.76℃/kW and 1℃/kW,respectively.Our research provides an effective solution for robust high-power all-fiber laser oscillators.
