Author Affiliations
Abstract
1 Shenzhen Key Laboratory of Laser Engineering, Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, State Key Laboratory of Radio Frequency Heterogeneous Integration, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
2 Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen, China
3 Han’s Laser Technology Industry Group Co., Ltd., Shenzhen, China
High-power femtosecond mid-infrared (MIR) lasers are of vast importance to both fundamental research and applications. We report a high-power femtosecond master oscillator power amplifier laser system consisting of a single-mode Er:ZBLAN fiber mode-locked oscillator and pre-amplifier followed by a large-mode-area Er:ZBLAN fiber main amplifier. The main amplifier is actively cooled and bidirectionally pumped at 976 nm, generating a slope efficiency of 26.9%. Pulses of 8.12 W, 148 fs at 2.8 μm with a repetition rate of 69.65 MHz are achieved. To the best of our knowledge, this is the highest average power ever achieved from a femtosecond MIR laser source. Such a compact ultrafast laser system is promising for a wide range of applications, such as medical surgery and material processing.
femtosecond fiber laser fluoride fiber amplifier master oscillator power amplifier mid-infrared High Power Laser Science and Engineering
2023, 11(4): 04000e53
Author Affiliations
Abstract
1 School of Physics and Optoelectronics, State Key Laboratory of Luminescent Materials and Devices, Guangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and Devices, Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, South China University of Technology, Guangzhou, China
2 Research Institute of Future Technology, South China Normal University, Guangzhou, China
In this work, we present a high-power, high-repetition-rate, all-fiber femtosecond laser system operating at 1.5 $\unicode{x3bc}$ m. This all-fiber laser system can deliver femtosecond pulses at a fundamental repetition rate of 10.6 GHz with an average output power of 106.4 W – the highest average power reported so far from an all-fiber femtosecond laser at 1.5 $\unicode{x3bc}$ m, to the best of our knowledge. By utilizing the soliton-effect-based pulse compression effect with optimized pre-chirping dispersion, the amplified pulses are compressed to 239 fs in an all-fiber configuration. Empowered by such a high-power ultrafast fiber laser system, we further explore the nonlinear interaction among transverse modes LP01, LP11 and LP21 that are expected to potentially exist in fiber laser systems using large-mode-area fibers. The intermodal modulational instability is theoretically investigated and subsequently identified in our experiments. Such a high-power all-fiber ultrafast laser without bulky free-space optics is anticipated to be a promising laser source for applications that specifically require compact and robust operation.
high-power femtosecond fiber laser high repetition rate intermodal modulational instability nonlinear pulse compression High Power Laser Science and Engineering
2023, 11(4): 04000e50
强激光与粒子束
2021, 33(11): 111008
1 北京大学人工微结构和介观物理国家重点实验室, 北京 100871
2 北京大学区域光纤通信网与新型光通信系统国家重点实验室, 北京 100871
研究了不同厚度周期极化铌酸锂晶体(PPLN)对掺铒飞秒光纤激光器倍频特性的影响。基于非线性偏振旋转锁模原理和啁啾脉冲放大技术,在1560 nm波段实现了重复频率为100 MHz,输出功率为423 mW,脉冲宽度为80 fs的掺铒飞秒光纤激光输出。以此为基频光源,对0.5,1,10 mm三种不同厚度PPLN倍频晶体进行倍频特性研究,实现了波长在780 nm的飞秒激光输出。其中采用0.5 mm晶体时获得了功率为100.4 mW、脉冲宽度为104 fs的倍频光输出,倍频转换效率为23.7%;采用1 mm晶体时获得了功率为165.0 mW、脉冲宽度为161 fs的倍频输出,倍频转换效率为39%;采用10 mm晶体时获得了功率为185.5 mW,脉冲宽度为305 fs的倍频光输出,倍频转换效率达43.7%。并解释了倍频转换效率和倍频光脉冲宽度随PPLN晶体厚度的变化规律。实验数据为基于锁模光纤激光器产生780 nm波段飞秒光脉冲的研究提供了有益的参考。
激光器 掺铒飞秒光纤激光器 啁啾脉冲放大器 非线性偏振旋转锁模 倍频 周期极化铌酸锂晶体 lasers erbium doped femtosecond fiber laser chirped pulse amplifier nonlinear polarization rotation mode locking second harmonic generation PPLN crystal
1 上海理工大学 光电信息与计算机工程学院, 上海 200093
2 华东师范大学 精密光谱科学与技术国家重点实验室, 上海 200062
介绍了超短脉冲偏振分割器的基本类型和放大器的光路布局, 总结了国内外采用偏振分割放大技术抑制光纤非线性效应、提高超短脉冲输出能量和突破增益介质抗损伤阈值方面的新进展。重点报道了偏振分割放大技术在高重复频率高功率掺铒飞秒激光器研制方面的最新进展, 基于双程放大结构和多级偏振分割, 同时实现超短脉冲的非线性放大与脉冲压缩, 结合光学倍频, 获得百毫瓦百飞秒, 中心波长780 nm的激光脉冲, 为实现结构紧凑、使用方便、环境稳定、光束质量好的飞秒激光光源提供了一个有效的技术途径, 有望部分替代钛宝石激光器, 在太赫兹产生、生物医学成像、光学非线性效应研究等方面拓展应用。
分割脉冲放大 光纤飞秒激光 相干合成 divided-pulse amplification femtosecond fiber laser coherent beam combination 红外与激光工程
2018, 47(1): 0103004
华中光电技术研究所—武汉光电国家实验室, 湖北 武汉 430223
目前,在被动锁模掺铒光纤激光器中,进行腔内色散补偿的方法主要包括:在激光谐振腔内熔接一段具有正常色散的光子晶体光纤、插入具有正常色散的光栅对，以及利用具有正常色散的啁啾光纤光栅等。针对目前腔内色散补偿方法存在的耦合效率低、环境稳定性差、色散量不易调节等不足，设计了一种由偏振合束器、色散补偿光纤和法拉第旋转镜构成的线形支路进行腔内色散精确补偿,采用透射式可饱和吸收体实现自启动锁模,并结合混合光器件,实验获得了重复频率为82.84 MHz、平均功率为10 mW、脉冲宽度为381 fs的飞秒脉冲保偏输出,作为种子源,可广泛应用于太赫兹产生、生物医学成像、超快光谱学等领域。
色散补偿 保偏 飞秒光纤激光器 可饱和吸收体 被动锁模 dispersion compensation polarization-maintaining femtosecond fiber laser SESAM passive mode-locking
1 天津大学精密仪器与光电子工程学院超快激光研究室， 光电信息技术教育部重点实验室， 天津 300072
2 西安中科汇纤光电科技有限公司， 陕西 西安 710119
利用普通大模场面积掺镱保偏双包层光纤作为增益介质，采用啁啾脉冲放大技术搭建了全保偏光纤飞秒激光放大系统。由于全保偏光纤结构，系统具有较高的集成度和长期稳定性。将系统中积累的三阶色散与放大过程中引入的非线性啁啾相互补偿，通过控制展宽光纤的长度，优化了压缩后脉冲质量和宽度。同时分析了周期性光谱调制对放大输出的影响，通过优化保偏（2+1）×1光纤合束器的制作工艺，解决了其引起的周期性光谱调制问题，最终获得重复频率为111 MHz，压缩后输出平均功率为9 W，对应脉宽为260 fs，单脉冲能量为81 nJ，保偏比为13 dB的高质量飞秒激光脉冲输出。
激光光学 保偏光纤合束器 周期性光谱调制 啁啾脉冲放大 光纤飞秒激光放大系统 laser optics polarization-maintaining fiber combiner periodic spectral modulation chirped-pulse amplification femtosecond fiber laser amplification system
南开大学 现代光学研究所 飞秒激光实验室, 天津 300071
介绍了一种适合于日常高校光学或光电技术专业的研究生和高年级本科生熟悉、了解飞秒激光教学实验用的飞秒光纤激光器。该飞秒激光光源基于非线性旋转偏振效应被动锁模原理, 输出脉冲宽度为440 fs、脉宽带宽积为0.362、中心波长在1560 nm附近、平均输出功率为12 mW、脉冲重复频率为31.15 MHz。
激光 飞秒光纤激光器 环形腔 非线性偏振旋转 被动锁模 laser femtosecond fiber laser ring cavity nonlinear polarization rotation passive mode locking
电子科技大学光电信息学院, 四川 成都 610054
利用波长为1560 nm的飞秒激光脉冲在高非线性光纤中产生孤子自频移，实现了140 nm范围可调谐的孤子脉冲输出。1560 nm的飞秒脉冲源是基于非线性偏振旋转技术的被动锁模掺Er3+光纤激光器，其脉冲宽度为300 fs，重复频率为13.7 MHz。将该飞秒脉冲输入至1010 m的高非线性光纤中，当输入脉冲的平均功率在0.15～0.8 mW范围内变化时，观察到了超短脉冲产生的孤子自频移现象，孤子脉冲的波长在1560～1700 nm范围内连续可调。基于非线性薛定谔方程，数值计算了飞秒脉冲在不同输入脉冲功率下产生的孤子自频移，并与实验进行了对比。研究结果在实现可调谐的飞秒激光脉冲源和全光模数转换等方面具有潜在的应用价值。
非线性光学 孤子自频移 飞秒光纤激光器 可调谐光源 nonlinear optics soliton self-frequency shift femtosecond fiber laser tunable optical source
