SESAM锁模全保偏光纤激光器重复频率的精确锁定

发布时间：2018-04-04 12:15

本文选题：光纤光学　切入点：光纤激光器　出处：《光学学报》2017年02期

【摘要】：实验采用共振增强式非线性折射率调制技术实现了半导体可饱和吸收镜锁模全保偏掺镱光纤激光器重复频率的精确锁定。在掺镱光纤激光器的腔内加入一个980/1064nm的波分复用器(WDM)和一段掺铒增益光纤,通过反馈控制加载在该掺铒光纤上的976nm抽运光LD2功率调控掺铒光纤的非线性折射率,进而对激光器的光学腔长实施控制,最终实现重复频率的精确锁定。优化了不同掺铒光纤长度及抽运光初始功率对激光器重复频率控制范围和锁定精度的影响。结果表明:当掺铒光纤长度为1.75m时,通过调整抽运光功率能够实现180Hz的重复频率调整范围;而重复频率的锁定精度仅与抽运光的初始功率密切相关,并不受掺铒光纤长度的明显影响。当LD2抽运光强度为18mW时,重复频率峰-峰值的波动范围小于0.5mHz,相应的标准偏差为0.16mHz,输出功率的标准偏差为0.009mW。此外,通过反馈控制抽运源LD1的强度,并取掉了腔内的掺铒增益光纤及与其相连的WDM,发现由于共振增强非线性和克尔非线性对光纤折射率的叠加,在稳定的单脉冲锁模区间内,重复频率单调变化的范围增加至1kHz,而锁定精度略有降低。
[Abstract]:The resonant enhanced nonlinear refractive index modulation technique has been used to realize the accurate locking of repetition frequency of the fully bias-preserving ytterbium-doped fiber laser in semiconductor saturable absorber mirror.A wavelength division multiplexer (WDM) of 980/1064nm and a section of erbium-doped gain fiber are added into the cavity of ytterbium-doped fiber laser. The nonlinear refractive index of erbium-doped fiber is controlled by feedback control of the power of the 976nm pumped light LD2 loaded on the erbium doped fiber.Then the optical cavity length of the laser is controlled, and the precise locking of the repetition rate is realized.The effects of the length of erbium-doped fiber and the initial power of the pump on the control range and locking accuracy of the laser repetition rate are optimized.The results show that when the length of erbium-doped fiber is 1.75m, the range of repetition rate adjustment of 180Hz can be realized by adjusting the pump power, and the locking accuracy of repetition rate is only closely related to the initial power of pumped light.It is not affected by the length of erbium-doped fiber.When the LD2 pump intensity is 18mW, the range of peak to peak repetition frequency is less than 0.5mHz, the corresponding standard deviation is 0.16mHz, and the standard deviation of output power is 0.009mW.In addition, the intensity of the pump source LD1 is controlled by feedback, and the erbium-doped gain fiber and its connected WDMs are removed from the cavity. It is found that in the stable monopulse mode-locked region, the resonance enhanced nonlinearity and Kerr nonlinear superposition of the refractive index of the fiber are found.The range of monotonic variation of repetition rate is increased to 1 kHz, while the locking accuracy is slightly reduced.
【作者单位】：上海理工大学光电信息与计算机工程学院;华东师范大学精密光谱科学与技术国家重点实验室;
【基金】：国家重大科学仪器设备开发专项(2012YQ150092) 国家自然科学基金(11404211) 上海市自然科学基金(13ZR1458100)
【分类号】：TN248

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