低重複頻率高能量全正常色散摻鐿光纖短脈衝鎖模雷射

Low Repetition Rate and High Energy Mode-Locked Yb-Doped Fiber Laser in AII Normal Dispersion Cavity

林家弘(Ja-Hon Lin) ； 朱家亮(Jia-Liang Jhu) ； 林鼎鈞(Ting-Chun Lin)

《科儀新知》 189期 (2012/08) Pp. 44-51

https://doi.org/10.29662/IT.201208.0005

摘要

波長在1 μm左右的高能量短脈衝光纖雷射具有許多實際的用途。為了降低脈衝重複頻率以提高脈衝能量，我們在全正常色散環型雷射腔內熔接了520公尺長的單模光纖，產生了365 kHz低重複頻率的鎖模短脈衝雷射。當雷射的輸出耦合率為80%時，所產生的鎖模短月正衝具有相當寬的頻寬，預期可以應用在生醫檢測上；當雷射耦合率提高到90%，最高輸出單一光脈衝的能量接近100 nJ。在此雷射架構下我們也發現了Q開關鎖模的現象，透過Q波包調變可以進一步降低鎖模脈衝的重複頻率，增加光脈衝輸出的強度。

並列摘要

It is revealed that high-energy pulses from fiber lasers around 1μm has various practical applications. For this purpose, we have generated 365 kHz low-repetition-rate pulses in all-normal-dispersion Yb-doped fiber ring laser by adding 520 m single mode fiber in the laser cavity. With 80% output coupler, the spectral bandwidth of mode-locked pulse is relative wide, which can be used in biomedical diagnosis. In use of 90% output coupler, the highest energy pulse around 100 nJ has been experimentally demonstrated. Besides, Q-switched mode-locking was observed in this laser configuration. By the modulating of Q-switching envelope, the repetition rate of mode-locked pulse can be further reduced to enhance the intensity of the output pulses.