摘要
2.3μm掺铥光纤激光器可广泛应用于环境气体检测、医学成像以及无创血糖测量等领域。基于掺铥光纤的2.3μm与1.9μm双波长激光级联放大技术可以有效抑制1.9μm波段放大自发辐射以及自激振荡,实现高功率2.3μm激光输出。2.3μm光纤激光器功率的进一步提高依赖于大模场面积单模掺铥光纤的发展。基于碲酸盐玻璃设计了一种纤芯直径为40μm的大模场单模掺铥实芯反谐振光纤,模拟结果显示,光纤在1.8~2.5μm的宽波段范围基模损耗均小于1 dB/m,同时高阶模式损耗大于10 dB/m,保证了激光的单模传输。基于该光纤的2.3μm与1.9μm级联光纤放大器仿真结果表明,所设计光纤在高功率单模2.3μm激光产生方面展现出显著优势。
Objective 2.3μm Tm-doped fiber lasers can be widely used in environmental gas detection,medical imaging,non-invasive blood glucose measurement and other fields.The 2.3μm and 1.9μm dual-wavelength laser cascaded amplification technology based on Tm-doped fiber can effectively suppress the amplified spontaneous emission and parasitic lasing in the 1.9μm band,and achieve high-power 2.3μm laser output.Further improvement of 2.3μm fiber laser power significantly depends on the development of large mode area single-mode Tm-doped fiber.Traditional core-cladding structure optical fiber has difficulty maintaining single-mode operation when the core diameter increases,resulting in degradation of the beam quality in laser system based on large-mode-area fiber.All-solid anti-resonant fiber has attracted widespread attention due to its properties on large mode area single-mode operation,wide transmission bandwidth,and flexible structural parameter design.Active fiber realized by doping rare earth ions in the fiber core has potential application in high-power fiber laser generation.A large mode area single-mode Tm-doped all-solid anti-resonant fiber with a core diameter of 40μm was designed based on tellurite glass,and a 2.3μm and 1.9μm cascade fiber amplifier based on this fiber was numerically simulated in this paper.Methods Comsol Multiphysics was used to build the fiber model,simulate fiber loss,get overlap integral,and design the anti-resonant fiber.Then,a numerical simulation model was built based on the rate equations of thulium ions and the power transmission equations of the amplifier,and was used in numerical simulation of the 1.9μm and 2.3μm dual-wavelength fiber amplifier based on the designed fiber.Results and Discussions Based on the mode coupling between the high-order modes and the cladding mode,an anti-resonant fiber with fundamental mode loss less than 1 dB/m,while the loss of all high-order modes greater than 10 dB/m in the 1.8-2.5μm band was demonstrated(Fig.3).The comparison of 2.3μm single-wavelength amplification and 1.9μm and 2.3μm dual-wavelength amplification shows that injecting 1.9μm seed light into the amplifier can effectively suppress amplified spontaneous emission in the 1.9μm band during 2.3μm laser amplification(Fig.4).Signal laser in 2.3-2.4μm band can be efficiently amplified(Fig.6).The slope efficiency of the dual-wavelength laser amplifier based on the designed fiber is about 30.6% for 1.9μm signal,and about 23.6% for 2.3μm signal with pump power of 100 W,and the 2.3μm signal can be amplified from 2 W to 24.8 W(Fig.7).Conclusions A single-mode Tm-doped tellurite all-solid anti-resonant fiber with core diameter of 40μm is designed,which achieves a fundamental mode loss of less than 1 dB/m in the 1.8-2.5μm band,and all high-order mode losses are greater than 10 dB/m,ensuring the single-mode transmission of signal light in the 1.9μm and 2.3μm bands.The numerical simulation of the 1.9μm and 2.3μm dual-wavelength fiber amplifier based on the designed fiber shows that the parasitic oscillation of the Tm-doped tellurite fiber amplifier in the 1.9μm band can be effectively suppressed by only using 0.2 W of 1.9μm seed light,and tens of watts of 2.3μm laser amplification can be achieved.It can be indicated that the designed fiber would exhibit good laser amplification performance in the wide band range of 2.3-2.4μm.The design process of the active all-solid antiresonant fiber proposed in this paper can be applied to the design of large mode area active fiber in other wavelength bands,which can serve as a reference for the design of large mode area single-mode fiber used in high-power fiber lasers and amplifiers.
作者
武天志
付士杰
赵红汝
许海琛
史春鹏
盛泉
史伟
姚建铨
WU Tianzhi;FU Shijie;ZHAO Hongru;XU Haichen;SHI Chunpeng;SHENG Quan;SHI Wei;YAO Jianquan(School of Precision Instrument and Opto-electronics Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Opto-electronics Information Technology(Ministry of Education),Tianjin University,Tianjin 300072,China;Academy of Opto-Electronics,China Electronics Technology Group Corporation(AOE CETC),Tianjin 300308,China)
出处
《红外与激光工程》
北大核心
2025年第8期1-8,共8页
Infrared and Laser Engineering
基金
广东省重点领域研发计划项目(2023B0909010005)
国家自然科学基金项目(62375201,62275190,62405218)
天津大学自主创新基金项目(2023XPD-0020)
天津市自然科学基金项目(23JCQNJC01740)
山东省重点研发计划项目(2021CXGC010202)
泰山产业领军人才项目(tscx202312163)。
关键词
实芯反谐振光纤
掺铥光纤
模式耦合
光纤放大器
all-solid anti-resonant fiber
Tm-doped fiber
mode coupling
fiber amplifier
