利用全偏振保持光纖環和主動相位調變之10 GHz鎖模摻鉺光纖雷射及高速光波長掃頻應用

Abstract

本論文的研究主要是利用全偏振保持光纖環來建構鎖模光纖雷射，所使用的增益介質為摻鉺光纖，並在光纖環裏加上相位調變器，利用相位調變器所能提供的相位調變去改變光纖環的相偏壓，如此一來也能改變光纖環的穿透率，從而成功達到主動鎖模。藉由適當選擇相位調變器的調變頻率，利用諧波鎖模技術能讓我們的雷射鎖模在10 GHz的高脈衝重覆率。我們進一步利用可電壓調控且能產生10 GHz高頻的介電質共振腔共振器 (DRO) 來作為調變訊號產生器，藉由改變共振器的調變頻率再透過雷射腔內的色散效應來改變鎖模光波長，進而製作出能夠在10 GHz高重覆率作高速掃頻的摻鉺光纖鎖模雷射，在8.5 kHz掃頻速度下掃頻範圍最大可以達到25 nm。

In this thesis work, we mainly utilize the polarization maintaining fibers for constructing the mode-locked fiber lasers. The gain fiber we use is the Er-doped fiber and an EO phase modulator is inserted into the optical fiber loop for active mode-locking. The travelling phase modulator can adjust the phase bias of the fiber loop and as a result, it can also change the fiber loop transmission. By suitably selecting the modulation frequency of the phase modulator, we successfully realize active mode-locking at the 10 GHz high repetition rate through the harmonic mode-locking technique. In addition, we use a voltage tuning dielectric resonator oscillator (DRO) as the 10 GHz signal generator to sweep the modulation frequency. We successfully achieve a 10 GHz high repetition rate mode-locked Er-doped fiber laser with high-speed optical wavelength sweeping capability. The widest sweep range is about 25 nm when the sweep rate is about 8.5 kHz.