纖衣幫浦之摻銩矽酸鹽光纖雷射之相關研究

Study of cladding-pumped Tm3+ doped silicate fiber laser

曾瀚緯(Han-Wei Tseng)

指導教授 ： 李穎玟

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2014年)

摘要

光纖雷射相較於一般傳統雷射有著高能源轉換效率、良好的光束品質、壽命長、較好的散熱係數、成本低等優點。在眾多雷射中，2μm波段雷射發展極為迅速，此波長對人眼相較於他波長更為安全且廣泛應用在醫療及工業上。
此研究所使用的7wt.%摻銩矽酸鹽光纖為目前文獻中摻雜濃度最高之摻銩矽酸鹽光纖。我們使用793nm半導體雷射作為幫浦光源，該波段對於銩離子有著交叉弛緩機制可使得量子效率可達200%。實驗可分為光纖雷射及光纖雷射放大器兩部分。其中光纖雷射部分又可依共振腔分為線性共振腔及環形共振腔兩種系統，所得到的輸出雷射斜效率分別為33.8%、15.9%，輸出波長為1978.4nm及2013nm，其中在摻銩矽酸鹽光纖中要能產生出超過2μm情形較少見。在光纖雷射放大器部份可以分成1985nm跟2013nm兩種種子光源；種子光源為1985nm時，固定輸入訊號能量為26.75mW情況下被放大至1.483W，此時增益為17.44dB；種子光源為2013nm輸入功率固定為0.55mW，可被放大至460mW，此時增益為18.2dB。
另外，我們也利用Liekki光纖模擬軟體進行模擬證明摻銩矽酸鹽光纖的自發放大(ASE)比摻銩二氧化矽光纖更適合應用於長波長，且也找出了幫浦源為793nm及1567nm且共振腔為HR-R4%情況下之增益光纖最佳長度；驗證了在放大器中不管在幫浦光源為793nm或1567nm，種子光源為1985nm輸出比種子光源2013nm高。

關鍵字

銩離子 ； 矽酸鹽光纖 ； 光纖雷射 ； 光纖放大器

並列摘要

In this thesis, we report on the theoretical and experimental investigation of a heavily Tm3+-doped silicate fiber. This silicate gain fiber has Tm3+ concentration of 7wt.% (8.35x1020/cm3). To the best of our knowledge, it is the highest concentration in Tm3+ doped fibers.The theoretical work is based on a commercial simulation code, LiekkiTM. Through the simulation, we verify that Tm3+ doped silicate fibers are more suitable than thulium-doped silica fibers for long-wavelength ASE emission. Furthermore, the laser and amplifier performance under the 793-nm and 1567-nm cladding pump are addressed. Finally, we experimentally demonstrate the potential of watt-level fiber amplifier and relatively long-wavelength fiber amplifier using the 50-cm 7wt.% Tm3+-doped silicate fiber. The 793nm laser diode was employed in our research to gain the advantage of “two-to-one” cross relaxation effect, enabling up to 200% quantum efficiency. The experiment work was divided into two parts. First, we have successfully developed linear and ring-cavity fiber laser at 1978.4 nm and 2013 nm with the slope efficiency of 33.8% and 15.9%, respectively. Second, a 1.48-W 1985-nm fiber amplifier as well as an 18.2 dB 2013-nm fiber amplifier were successfully demonstrated.

並列關鍵字

Thulium ； Silicate fiber ； Fiber laser ； Fiber amplifier

參考文獻

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