相位跡變匹配級聯光參振盪與倍頻高效率寬頻藍光雷射鉭酸鋰晶片之研製

本篇論文主要由三大部分構成: 1. 準相位匹配理論與光參振盪器原理之介紹。 2. 光參-倍頻藍光雷射晶片之設計與研製。 3. 光參-倍頻藍光雷射晶片之光學量測與特性分析。理論部分，先介紹非線性頻率轉換與準相位匹配理論，最後推導出光參振盪器以及倍頻轉換理論，根據理論去計算鉭酸鋰晶體在不同的操作溫度下，滿足準相位匹配光參與倍頻轉換的週期。利用本實驗室發展的鎳金屬內擴散配合高電壓致極化反轉製程技術，應用於厚度0.75mm之共熔鉭酸鋰晶片製作。實驗中設計了級聯光參-倍頻藍光雷射晶片，光參部分週期為7.7576μm，而倍頻部分採變跡式多週期結構設計，從4.92μm至5.06μm以0.01μm的等差遞增，共15種週期，成功研製出長16mm高效率寬頻藍光雷射晶片。光學量測部分，利用7ns/500Hz 532nm綠光雷射做為泵浦源，設計一可共振930nm波段之共振腔，將所研製之雷射晶片置入，量測此光參振盪器之出光轉換效率。我們成功以946mW綠光泵浦變跡多週期光參-倍頻藍光雷射晶片，配合雷射共焦腔之設計，實現頻寬約1.83nm，斜線效率19.6%之高效率寬頻藍光，此泵浦功率下出光106mW。

關鍵字

準相位匹配；非線性光學；鉭酸鋰；相位跡變

並列摘要

This thesis is composed of three parts : (1)The theory of quasi-phase-matching(QPM) and the QPM optical parametric oscillator(OPO). (2)The design and fabrication technique of periodically poled congruent grown lithium tantalite(LiTaO3) 465nm blue laser chip based on QPM cascaded OPO-SHG structure. (3)The measurement and analysis of OPO-SHG blue light generators. First of all, the mechanism of nonlinear frequency conversion and QPM theory and its application to optical parameter and second harmonic generation is introduced. By using Sellmeier’s equation, the QPM period of PPLT for the proposed structure is calculated. By taking advantage of the nickel-diffusion assisted electric poling process, cascaded OPO-SHG devices on a 0.75mm-thick congruent LiTaO3 substrate is fabricated. The OPO-SHG device has a QPM period of 7.7576μm in the OPO segment. An apodized structure is designed in the SHG segment, which is composed of 15 different QPM periods ranging from 4.92μm to 5.06μm with an increment of 0.01μm. The total length of this cascaded OPO-SHG device is 16mm. Using a 7ns/500Hz 532nm green laser as the pump source, the OPO-SHG device is placed into the OPO cavity in which the 930nm signal wave oscillates, and a 465nm broadband blue laser is shown to be generated. The output power of the generated blue light is 106mW with a 532nm pump source of 946mW. The linewidth and slope efficiency of the spectrum are shown to be 1.83nm and 19.6%, respectively.