非週期性晶疇極化反轉鈮酸鋰作為雙波長電光布拉格雷射Q調制器之研究

Aperiodically Poled Lithium Niobate as Electro-Optical Bragg Q-switch in Dual Wavelength Laser

黃尚昇(Shang-Sheng Huang)

指導教授 ： 陳彥宏

國立中央大學/理學院/光電科學與工程學系/碩士(2014年)

摘要

橘黃光脈衝雷射，可應用天文觀測和醫療領域。在實驗上利用非週期性晶疇極化反轉鈮酸鋰同時Q調制1064nm雷射和1342nm雷射並利用BiBO晶體和頻產生橘黃光脈衝雷射。以模擬退火法演算法，計算可滿足1064nm和1342nm雷射繞射條件的非週期性結構。入射光的光束大小、非週期性結構的面積…等，皆會影響繞射效率。然而，非週期性晶疇極化反轉鈮酸鋰在結構中的模態耦合方程式複雜，尚未有理論發表，因此先以實驗作為佐證
在考量入射光束大小為300μm的情況下，本實驗元件設計長度均為3cm，但寬度不同，分別為920μm和560μm。寬度960μm的設計，結構涵蓋入射光與繞射光；而寬度560μm的設計只考量入射光。兩種結構經反傅立葉分析過後，其空間頻率所對應到的傅立葉係數，幾乎相等。我們在寬度960μm的元件，入射光入射元件中間位置時，量測到最佳的繞射效率。將此元件，做為在Nd:YVO4雷射系統下，雙波長雷射Q調制並利用BIBO和頻產生橘黃光脈衝雷射。在共振腔優化最佳程度下，吸收泵浦為5.8W，達成橘黃光脈衝雷射輸出。脈衝寬度9ns，尖端峰值功率270W。

關鍵字

非週期性晶疇極化反轉鈮酸鋰

並列摘要

Yellow-orange pulsed lasers are required for astronomic observation and medical applications. We have succeed design and manufacture aperiodically poled lithium niobate(APPLN) as EO Bragg Q switching in Nd:YVO4 dual wavelength sum frequency generate Orange-Yellow pulse laser.
In this letter, we design APPLN by aperiodic optical superlattice technique and simulated annealing method. Beam spot size of incident light, aperiodically structure area and other reason effect diffraction efficiency. However, the coupled mode theory in APPLN is complicated, so the theory haven’t been publish.
The beam spot size of the incident light is about 300μm, we design two device. The first device which width is 920μm design for incident light and diffraction light, and the second device which width is 560μm design for incident light only. Both length is 3cm and thickness is 500μm.
We can measure different diffraction efficiency with different incident light position. When the incident light input the device’s middle position of the width dimension, we get the highest diffraction efficiency at the first device. Then we put the first device into laser cavity. Under the optimum cavity-length condition, the highest Orange-Yellow pulse laser peak power is 270W, pulse width is 9ns, obtained at 5.8W of absorption pump power.

並列關鍵字

APPLN

參考文獻

[1.26] 曾冠翔，" 以電光非週期性晶格極化反轉鈮酸鋰晶體應用於雙波長雷射系統之腔內布拉格繞射元件之設計與研究Aperiodic Poled Lithium Niobate Electro-optic Bragg Deflector as an Efficiency Laser Q-switch in a Dual-wavelength Solid-State Laser "，國立中央大學光電科學與工程研究所碩士論文，中華民國100年六月

[3.3] 呂學璁，"以非週期性晶疇極化反轉鈮酸鋰晶體作為電光波長調變光參量產生器Active Telecom-Band Wavelength tuning

Jin-Song Zhu, Zhen Yang, and Ye-Ning Wang, “Enhancement of

[3.2] Ben-Yuan Gu, Yan Zhang, Bi-Zhen Dong, “Investigations of

[3.7] Duan Feng, Nai-Ben Ming, Jing-Fen Hong, Yong-Shun Yang,