非同步諧波鎖模摻鐿光纖雷射之雷射動力學

Abstract

非同步諧波鎖模光纖雷射具有許多的特性，在光通訊、生醫光電或者超快光學等應用之發展上有很好的潛在價值，這些優良特性包括具高超模噪音抑制比，以及可形成超高重複率且超短的脈衝序列。

在此論文之中，我們首次利用偏振疊加波鎖模、相位調變和環形共振腔在摻鐿的雷射系統中成功達到主被動同步諧波鎖模及非同步諧波鎖模，是首次在正色散介質觀察到非同步諧波鎖模的研究工作。其鎖模脈衝重複率為10 GHz，非同步偏差頻率可達94 kHz，而雷射系統在非同步諧波鎖模狀態下之超模噪音抑制比達到60 dB，較同步諧波鎖模狀態增進40dB。雷射輸出功率達20 mW，且波長操作在1050 nm，使得此雷射在包括生醫光電等應用上也有很大的發展潛力。

Asynchronous Harmonic Mode-Locked Ytterbium Doped Fiber Lasers have many characteristics which are of great application potentials in the fields of long-distance optical communication, bio-photonics and ultrafast optics. These advantages include higher super-mode suppression ratios and the capability of generating ultrahigh repetition rate and ultra-short pulse trains.

In this thesis, we demonstrate for the first time an asynchronous harmonic mode-locked ytterbium doped fiber laser with the hybrid mode-locking technique. This is the first observation of the asynchronous harmonic mode-locking in a normal dispersion fiber cavity. The deviation frequency of the laser is 94 kHz and the super-mode suppression ratio is around 60 dB at the 10 GHz asynchronous harmonic mode-locked state. The super-mode suppression ratio increases around 40 dB than the ordinary harmonic mode-locked state. The output power is around 20 mW operating at 1050 nm, a useful wavelength in many applications including bio-photonics.