高功率全光纤1.6微米类噪声方形脉冲激光器  

High-power 1.6μm noise-like square pulse generation in an all-fiber mode-locked laser

作　　者：窦志远 张斌[1,2,3] 刘帅林 侯静 Dou Zhi-Yuan;Zhang Bin;Liu Shuai-Lin;Hou Jing(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,China;State Key Laboratory of Pulsed Power Laser Technology,Changsha 410073,China;Hunan Provincial Key Laboratory of High Energy Laser Technology,Changsha 410073,China)

机构地区：[1]国防科技大学前沿交叉学科学院,高能激光技术研究所,长沙410073 [2]脉冲功率激光技术国家重点实验室,长沙410073 [3]高能激光技术湖南省重点实验室,长沙410073

出　　处：《物理学报》2020年第16期93-100,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61435009,61235008,61405254).

摘　　要：报道了一种工作波长在1.6μm的哑铃形结构高功率铒镱共掺全光纤锁模激光器.无隔离器结构设计以及大模面积双包层铒镱共掺光纤的使用,使振荡器可稳定高效地工作于较高泵浦功率下.证明了不同带内吸收系数的铒镱共掺光纤对输出波长有极其重要的影响,带内吸收调控可作为一种有效的波长控制方法.实验中,利用高带内吸收光纤获得了稳定的1.6μm高功率、大能量纳秒类噪声方形脉冲输出,最大平均输出功率和单脉冲能量分别为1.16 W和1.26μJ.同时研究了附加插入损耗对所设计激光器输出特性的影响,当总附加插入损耗为10 dB时,激光器仍然可以稳定发射1.6μm类噪声方形脉冲,说明利用高带内吸收系数的铒镱共掺光纤设计的激光器对1.6μm输出波长具备极强的鲁棒性.对于过大的附加插入损耗,1.6μm输出波长会被完全抑制.We demonstrate generation of high-power and large-energy noise-like square pulses at 1612 nm in an allfiber dumbbell-shaped mode-locked Er: Yb co-doped double-clad fiber(EYDF) laser. The custom couplers with high power handling keep the laser function well. Large-mode-area EYDF with high power handling and enough high pump power make it possible to obtain high output power in the oscillator. Compared with figure-eight structure, strictly all-fiber dumbbell-shaped structure without isolator and optimizing splicing loss could reduce intra-cavity loss and improve optical to optical efficiency, which could reduce heat accumulation and enhance the power carrying capacity of EYDF. In order to study the influence of in-band absorption on output wavelength, EYDF1 and EYDF2 with different in-band absorption coefficients are accessed to intracavity,respectively. It is directly demonstrated that regulation of in-band absorption is an effective way to control the output wavelength. Strong in-band absorption could restrain the emission of C-band and make the wavelength range above 1.6 μm obtain enough gain. Linear insertion loss is another important factor to affect the emission wavelength in EYDF fiber laser. At pump power of 8 W, maximum average output power with emission wavelength above 1.6 μm can reach 1.16 W, corresponding to a single pulse energy of 1.26 μJ. SNR of output pulse is 70 dB which indicates the high stability of mode-locking. In order to verify and evaluate influence of insertion loss on the output characteristics of mode-locked laser, a variable attenuator is inserted in experimental setup, allowing us adjust the linear loss of the cavity. By increasing pump power and adjusting PCs, mode-locked pulses could be obtained on the condition of large additional insertion loss. Even though ~ 10 dB additional insertion loss is introduced, the oscillation still could function at 1612 nm and keep stable modelocked state. This result demonstrates our oscillation could bear strong additional loss and own strong rob

关 键 词：全光纤激光器 类噪声脉冲 锁模 

分 类 号：TN248[电子电信—物理电子学]