We demonstrate an integrated all-fiber mid-infrared(mid-IR)supercontinuum(SC)source generated by a 1.95μm master oscillator power amplifier system and a single-mode ZBLAN(ZrF_4–BaF_2–LaF_3–AlF_3–NaF)fiber.The max...We demonstrate an integrated all-fiber mid-infrared(mid-IR)supercontinuum(SC)source generated by a 1.95μm master oscillator power amplifier system and a single-mode ZBLAN(ZrF_4–BaF_2–LaF_3–AlF_3–NaF)fiber.The maximum average output power is 10.67 W with spectral bandwidth covering from～1.9 to 4.1μm.The single-mode ZBLAN fiber and silica fiber are thermal-spliced to enhance the robustness and practicability of the system.It is,to the best of our knowledge,the first high-power integrated compacted all-fiber mid-IR SC source based on thermal-spliced silica fiber and ZBLAN fiber.展开更多
We report an all-fiberized 30-W supercontinuum(SC) generation in a piece of ZrF4-BaF2-LaF3-AlF3-NaF(ZBLAN) fiber. The pump source is a thulium-doped fiber amplifier(TDFA) with broadband output spectrum spanning the 1....We report an all-fiberized 30-W supercontinuum(SC) generation in a piece of ZrF4-BaF2-LaF3-AlF3-NaF(ZBLAN) fiber. The pump source is a thulium-doped fiber amplifier(TDFA) with broadband output spectrum spanning the 1.9 to 2.6 μm region. The used ZBLAN fiber has a core diameter of 10 μm, and was directly fusion-spliced to the pigtail of the TDFA without using a traditional mode field adapter(MFA) or a piece of transition fiber. Such a low-loss and robust fusion splice joint, together with a robust AlF3-fiber-based endcap,enables efficient and high-power SC generation in the ZBLAN fiber. An SC with an average power up to 30.0 W and a spectral coverage of 1.9–3.35 μm with 20-dB bandwidth of 1.92–3.20 μm was obtained. Moreover, an SC with a broader spectrum was achieved by raising the pump pulse peak power(via reducing the duty ratio of the pump laser pulse). An SC with an output power of 27.4 W and a spectral coverage of 1.9–3.63 μm(with 20-dB bandwidth of 1.92–3.47 μm) was obtained, as well as an SC with output power of 24.8 W and a spectral coverage of 1.9–3.70 μm(with 20-dB bandwidth of 1.93–3.56 μm). The power conversion efficiency was measured as>69%. To the best of the authors’ knowledge, this research demonstrates the record output power of SC lasers based on ZBLAN fibers, paving the way for broadband and efficient multi-tens-of-watts SC generation in softglass fibers.展开更多
A spectrally flat mid-infrared supercontinuum(MIR-SC) spanning 2.8–3.9 μm with a maximum output power of 411 mW was generated in a holmium-doped ZBLAN fiber amplifier(HDZFA). A broadband fiber-based SC covering the ...A spectrally flat mid-infrared supercontinuum(MIR-SC) spanning 2.8–3.9 μm with a maximum output power of 411 mW was generated in a holmium-doped ZBLAN fiber amplifier(HDZFA). A broadband fiber-based SC covering the 2.4–3.2 μm region was designed to seed the amplifier. Benefiting from the broadband seed laser,the obtained SC had a high spectral flatness of 3 dB over the range of 2.93–3.70 μm(770 nm). A spectral integral showed that the SC power beyond 3 μm was 372 mW, i.e., a power ratio of 90.6% of the total power. This paper,to the best of our knowledge, not only demonstrates the first spectrally flat MIR-SC directly generated in fluoride fiber amplifiers, but also reports the highest power ratio beyond 3 μm obtained in rare-earth-doped fluoride fiber until now.展开更多
Based on the rate equations describing the erbium-doped fluoride glass （ZBLAN） fibre lasers with different pumping configurations being taken into account, this paper presents theoretical calculations related to the...Based on the rate equations describing the erbium-doped fluoride glass （ZBLAN） fibre lasers with different pumping configurations being taken into account, this paper presents theoretical calculations related to the dynamic population density and the operation performance of a high power mid-infrared all-fibre erbium-doped ZBLAN fibre laser. It shows that the ground-state absorption, excited-state absorption and energy-transfer-upconversion processes co-exist and produce a population balance, causing the laser to operate stably at a continuous wave state. A good agreement between the theoretical results and recent experimental measurement is obtained. Furthermore, the laser structure parameters including fibre length, reflectance of output fibre Bragg grating and pumping configurations are quantitatively optimised to achieve the best performance. The results show, as expected, that the slope efficiency of the fibre laser can be improved significantly through optimisation, which then provides an important guide for the design of high-performance mid-infrared erbium-doped ZBLAN fibre lasers.展开更多
A new method to achieve 2-μm pulsed fiber lasers based on a supercontinuum （SC） is demonstrated. The incident pump light is a pulsed SC which contains a pump light and a signal light at the same time. The initial s...A new method to achieve 2-μm pulsed fiber lasers based on a supercontinuum （SC） is demonstrated. The incident pump light is a pulsed SC which contains a pump light and a signal light at the same time. The initial signal of the seed laser is provided by the incident pump light and amplified in the cavity. Based on this, we obtain a 2-μm pulsed laser with pulse repetition rate of 50 kHz and pulse width of 2 ns from the Tm-doped fiber laser. This 2-μm pulsed laser is amplified by two stages of fiber amplifiers, then the amplified laser is used for mid-infrared （mid-IR） SC generation in a 10-m length of ZrF4-BaF2-LaF3-AIF3-NaF （ZBLAN） fiber. An all-fiber-integrated mid-IR SC with spectrum ranging from 1.8 ~tm to 4.3 μm is achieved. The maximal average output power of the mid-IR SC from the ZBLAN fiber is 1.24 W （average output power beyond 2.5 μm is 340 mW）, corresponding to an output efficiency of 6.6% with respect to the 790-nm pump power.展开更多
976 nm+1976 nm dual-wavelength pumped Er-doped ZBLAN fiber lasers are generally accepted as the preferred solution for achieving 3.5μm lasing.However,the 2μm band excited state absorption from the upper lasing level...976 nm+1976 nm dual-wavelength pumped Er-doped ZBLAN fiber lasers are generally accepted as the preferred solution for achieving 3.5μm lasing.However,the 2μm band excited state absorption from the upper lasing level(^(4 )F_(9/2)→^(4)F_(7/2))depletes the Er ions population inversion,reducing the pump quantum efciency and limiting the power scaling.In this work,we demonstrate that the pump quantum efciency can be efectively improved by using a long-wavelength pump with lower excited state absorption rate.A 3.5μm Er-doped ZBLAN fber laser was built and its performances at diferent pump wavelengths were experimentally investigated in detail.A maximum output power at 3.46μm of~7.2 W with slope efciency(with respect to absorbed 1990 nm pump power)of 41.2%was obtained with an optimized pump wavelength of 1990 nm,and the pump quantum efciency was increased to 0.957 compared with the 0.819 for the conventional 1976 nm pumping scheme.Further power scaling was only limited by the available 1990 nm pump power.A numerical simulation was implemented to evaluate the cross section of excited state absorption via a theoretical ftting of experimental results.The potential of further power scaling was also discussed,based on the developed model.展开更多
The upconversion luminescence of several YbEr co-doped Zr-Ba-La-Al-Na(ZBLAN)glass samples(Er(0.5)Yb(3):ZBLAN,Er(0.5)Yb(1):ZBLAN and Er(0.5):ZBLAN)has been studied.A new kind of upconversion cooperative radiation fluor...The upconversion luminescence of several YbEr co-doped Zr-Ba-La-Al-Na(ZBLAN)glass samples(Er(0.5)Yb(3):ZBLAN,Er(0.5)Yb(1):ZBLAN and Er(0.5):ZBLAN)has been studied.A new kind of upconversion cooperative radiation fluorescence,which comes from coupled cluster states of two Yb^(3+)ions has been observed.This is significant in that it may lead to a new path to achieve blue upconversion luminescence,which has promising upconversion applications.展开更多
We have experimentally demonstrated the flat supercontinuum(SC)generation using a 10-m-long ZrF4-BaF2-LaF3-AlF3-NaF(ZBLAN)fluoride fiber pumped by an erbium-doped mode-locked fiber laser incorporating carbon-nanotube-...We have experimentally demonstrated the flat supercontinuum(SC)generation using a 10-m-long ZrF4-BaF2-LaF3-AlF3-NaF(ZBLAN)fluoride fiber pumped by an erbium-doped mode-locked fiber laser incorporating carbon-nanotube-based saturable absorbers.In order to improve the spectral flatness of SC,the standardized single-mode fiber with different lengths is connected to the output of the mode-locked fiber laser before the pulse amplification.The generated SC with ZBLAN fiber exhibits the best spectral flatness with fluctuation less than 1.29 dB over the wavelength of 1571.8 nm−1803.1 nm,showing potential applications in optical sensing.展开更多
The enhanced laser cooling performance of rare-earth-ions-doped glasses containing small particles is predicted. This is achieved by the enhancement of local field around rare earth ions, owing to the surface plasmon ...The enhanced laser cooling performance of rare-earth-ions-doped glasses containing small particles is predicted. This is achieved by the enhancement of local field around rare earth ions, owing to the surface plasmon resonance of small metallic particles. The role of energy transfer between ions and the particle is theoretical discussed. Depending on the particle size and the ion emission quantum efficiency, the enhancement of the absorption and the fluorescence is predicted. Moreover, taking Yb^3＋-doped ZBLAN as example, the cooling power and heat-light converting efficiency are calculated. It is finally concluded that the absorption and the fluorescence are greatly enhanced in these composite materials, the cooling power is increased compared to the bulk material.展开更多
基金National High-tech R&D Program of China(863 Program)(2015AA021102)Innovative Research and Development Project of Nanshan District(KC2013JSCX0013A)+3 种基金China Postdoctoral Science Foundation(2015M572353,2015M582407)Natural Science Foundation of SZU(201457)National Natural Science Foundation of China(NSFC)(61275144,61308049)Science and Technology Projects of Shenzhen City(JCYJ20130329103213543,JCYJ20140418091413568,JCYJ20150324140036862)
文摘We demonstrate an integrated all-fiber mid-infrared(mid-IR)supercontinuum(SC)source generated by a 1.95μm master oscillator power amplifier system and a single-mode ZBLAN(ZrF_4–BaF_2–LaF_3–AlF_3–NaF)fiber.The maximum average output power is 10.67 W with spectral bandwidth covering from～1.9 to 4.1μm.The single-mode ZBLAN fiber and silica fiber are thermal-spliced to enhance the robustness and practicability of the system.It is,to the best of our knowledge,the first high-power integrated compacted all-fiber mid-IR SC source based on thermal-spliced silica fiber and ZBLAN fiber.
基金National Natural Science Foundation of China(NSFC)(61235008,61405254,61435009)
文摘We report an all-fiberized 30-W supercontinuum(SC) generation in a piece of ZrF4-BaF2-LaF3-AlF3-NaF(ZBLAN) fiber. The pump source is a thulium-doped fiber amplifier(TDFA) with broadband output spectrum spanning the 1.9 to 2.6 μm region. The used ZBLAN fiber has a core diameter of 10 μm, and was directly fusion-spliced to the pigtail of the TDFA without using a traditional mode field adapter(MFA) or a piece of transition fiber. Such a low-loss and robust fusion splice joint, together with a robust AlF3-fiber-based endcap,enables efficient and high-power SC generation in the ZBLAN fiber. An SC with an average power up to 30.0 W and a spectral coverage of 1.9–3.35 μm with 20-dB bandwidth of 1.92–3.20 μm was obtained. Moreover, an SC with a broader spectrum was achieved by raising the pump pulse peak power(via reducing the duty ratio of the pump laser pulse). An SC with an output power of 27.4 W and a spectral coverage of 1.9–3.63 μm(with 20-dB bandwidth of 1.92–3.47 μm) was obtained, as well as an SC with output power of 24.8 W and a spectral coverage of 1.9–3.70 μm(with 20-dB bandwidth of 1.93–3.56 μm). The power conversion efficiency was measured as>69%. To the best of the authors’ knowledge, this research demonstrates the record output power of SC lasers based on ZBLAN fibers, paving the way for broadband and efficient multi-tens-of-watts SC generation in softglass fibers.
基金National Natural Science Foundation of China(NSFC)(61435009)
文摘A spectrally flat mid-infrared supercontinuum(MIR-SC) spanning 2.8–3.9 μm with a maximum output power of 411 mW was generated in a holmium-doped ZBLAN fiber amplifier(HDZFA). A broadband fiber-based SC covering the 2.4–3.2 μm region was designed to seed the amplifier. Benefiting from the broadband seed laser,the obtained SC had a high spectral flatness of 3 dB over the range of 2.93–3.70 μm(770 nm). A spectral integral showed that the SC power beyond 3 μm was 372 mW, i.e., a power ratio of 90.6% of the total power. This paper,to the best of our knowledge, not only demonstrates the first spectrally flat MIR-SC directly generated in fluoride fiber amplifiers, but also reports the highest power ratio beyond 3 μm obtained in rare-earth-doped fluoride fiber until now.
基金supported by the China Postdoctoral Science Foundation (Grant No. 20090451417)the China Postdoctoral Science Special Foundation (Grant No. 201003693)+1 种基金the Fundamental Research Funds for the Central Universities of China (Grant No. ZYGX2009J053)the National Natural Science Foundation of China (Grant No. 60736038)
文摘Based on the rate equations describing the erbium-doped fluoride glass （ZBLAN） fibre lasers with different pumping configurations being taken into account, this paper presents theoretical calculations related to the dynamic population density and the operation performance of a high power mid-infrared all-fibre erbium-doped ZBLAN fibre laser. It shows that the ground-state absorption, excited-state absorption and energy-transfer-upconversion processes co-exist and produce a population balance, causing the laser to operate stably at a continuous wave state. A good agreement between the theoretical results and recent experimental measurement is obtained. Furthermore, the laser structure parameters including fibre length, reflectance of output fibre Bragg grating and pumping configurations are quantitatively optimised to achieve the best performance. The results show, as expected, that the slope efficiency of the fibre laser can be improved significantly through optimisation, which then provides an important guide for the design of high-performance mid-infrared erbium-doped ZBLAN fibre lasers.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61235008 and 61077076)
文摘A new method to achieve 2-μm pulsed fiber lasers based on a supercontinuum （SC） is demonstrated. The incident pump light is a pulsed SC which contains a pump light and a signal light at the same time. The initial signal of the seed laser is provided by the incident pump light and amplified in the cavity. Based on this, we obtain a 2-μm pulsed laser with pulse repetition rate of 50 kHz and pulse width of 2 ns from the Tm-doped fiber laser. This 2-μm pulsed laser is amplified by two stages of fiber amplifiers, then the amplified laser is used for mid-infrared （mid-IR） SC generation in a 10-m length of ZrF4-BaF2-LaF3-AIF3-NaF （ZBLAN） fiber. An all-fiber-integrated mid-IR SC with spectrum ranging from 1.8 ~tm to 4.3 μm is achieved. The maximal average output power of the mid-IR SC from the ZBLAN fiber is 1.24 W （average output power beyond 2.5 μm is 340 mW）, corresponding to an output efficiency of 6.6% with respect to the 790-nm pump power.
基金supported by the National Natural Science Foundation of China(Grant Nos.62105240,62075159,61975146,and 62275190)Shandong Province Key R&D Program(Nos.2020CXGC010104 and 2021CXGC010202)Seed Foundation of Tianjin University(No.2023XPD-0020).
文摘976 nm+1976 nm dual-wavelength pumped Er-doped ZBLAN fiber lasers are generally accepted as the preferred solution for achieving 3.5μm lasing.However,the 2μm band excited state absorption from the upper lasing level(^(4 )F_(9/2)→^(4)F_(7/2))depletes the Er ions population inversion,reducing the pump quantum efciency and limiting the power scaling.In this work,we demonstrate that the pump quantum efciency can be efectively improved by using a long-wavelength pump with lower excited state absorption rate.A 3.5μm Er-doped ZBLAN fber laser was built and its performances at diferent pump wavelengths were experimentally investigated in detail.A maximum output power at 3.46μm of~7.2 W with slope efciency(with respect to absorbed 1990 nm pump power)of 41.2%was obtained with an optimized pump wavelength of 1990 nm,and the pump quantum efciency was increased to 0.957 compared with the 0.819 for the conventional 1976 nm pumping scheme.Further power scaling was only limited by the available 1990 nm pump power.A numerical simulation was implemented to evaluate the cross section of excited state absorption via a theoretical ftting of experimental results.The potential of further power scaling was also discussed,based on the developed model.
基金Supported by the National Natural Science Foundation of China under Grant No.19874033the Open Research Fund of the Institute of Physics and the Institute of Semiconductor Physics,Chinese Academy of Sciencesthe State Kay Program for Basic Research in China(G1998061311).
文摘The upconversion luminescence of several YbEr co-doped Zr-Ba-La-Al-Na(ZBLAN)glass samples(Er(0.5)Yb(3):ZBLAN,Er(0.5)Yb(1):ZBLAN and Er(0.5):ZBLAN)has been studied.A new kind of upconversion cooperative radiation fluorescence,which comes from coupled cluster states of two Yb^(3+)ions has been observed.This is significant in that it may lead to a new path to achieve blue upconversion luminescence,which has promising upconversion applications.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.61605108,61635006,and 61735009)Shanghai Young Oriental Scholar 2016(Grant No.QD2016025).
文摘We have experimentally demonstrated the flat supercontinuum(SC)generation using a 10-m-long ZrF4-BaF2-LaF3-AlF3-NaF(ZBLAN)fluoride fiber pumped by an erbium-doped mode-locked fiber laser incorporating carbon-nanotube-based saturable absorbers.In order to improve the spectral flatness of SC,the standardized single-mode fiber with different lengths is connected to the output of the mode-locked fiber laser before the pulse amplification.The generated SC with ZBLAN fiber exhibits the best spectral flatness with fluctuation less than 1.29 dB over the wavelength of 1571.8 nm−1803.1 nm,showing potential applications in optical sensing.
基金supported by the National Natural Science Foundation of China under Grant Nos.10434060 and 10674047the Doctor Foundation of the Ministry of Education under Grant No.20040269010Shanghai Priority Academic Discipline,and the 211 Foundation of the Ministry of Education Doctor Program Scholarship Fund of ECNU 2007
文摘The enhanced laser cooling performance of rare-earth-ions-doped glasses containing small particles is predicted. This is achieved by the enhancement of local field around rare earth ions, owing to the surface plasmon resonance of small metallic particles. The role of energy transfer between ions and the particle is theoretical discussed. Depending on the particle size and the ion emission quantum efficiency, the enhancement of the absorption and the fluorescence is predicted. Moreover, taking Yb^3＋-doped ZBLAN as example, the cooling power and heat-light converting efficiency are calculated. It is finally concluded that the absorption and the fluorescence are greatly enhanced in these composite materials, the cooling power is increased compared to the bulk material.
