一維/二維晶疇工程準相位匹配元件作為Q調制器、(多)波長轉換器及頻譜電光調控器並應用於雷射及光參量振盪器之研究;1D/2D domain engineered QPM devices for Q-switching, (multi-)wavelength conversion, and spectrum tailoring in lasers and optical parametric oscillators

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/68311

Title:	一維/二維晶疇工程準相位匹配元件作為Q調制器、(多)波長轉換器及頻譜電光調控器並應用於雷射及光參量振盪器之研究;1D/2D domain engineered QPM devices for Q-switching, (multi-)wavelength conversion, and spectrum tailoring in lasers and optical parametric oscillators
Authors:	張煒堃;Chang,Wei-Kun
Contributors:	光電科學與工程學系
Keywords:	準相位匹配;Q調制器;電光調控器;波長轉換器;光參量振盪器;鈮酸鋰;QPM;Q-switch;EO;NLO;OPO;Lithium Niobate
Date:	2015-07-24
Issue Date:	2015-09-23 11:19:34 (UTC+8)
Publisher:	國立中央大學
Abstract:	雷射科技已經廣泛地運用在各式領域中，如光通訊、生醫、顯示技術、遙測和環境檢測；而這些應用所需要的特定波段和光源特性大都可利用獨特且可設計的非線性光子晶體之準相位匹配技術和電光調制能力來達成。延續過往的研究成果，本論文展示了在鈮酸鋰晶體上製作出一維或二維且週期性乃至非週期性結構，配合該晶體優良的非線性波長轉換和電光調制的能力，作為有效率地積體化多功的主動式雷射元件。前兩章，先說明研究動機、背景和鈮酸鋰晶體的電光特性。接著在第三章介紹如何利用二維光子晶體來同時達成Ｑ調制和光參量增益元件。在二維週期性極化反轉鈮酸鋰晶體和鎂銣摻雜週期性極化反轉鈮酸鋰晶體利用溫度調變達成通訊波段光源連續調變的結果也有介紹。隨後，介紹如何利用非週期超晶格的技術和模擬退火法的優化在鈮酸鋰晶體上設計並製作出符合要求的元件。憑藉著開發出的演算程式，設計出各式一維/二維非線性光子晶體結構來達成如電光Q調制、電光模態轉換器、腔內和頻、腔內倍頻、以及腔內光參量振盪器來達成各種應用所需的雷射光源。除了利用非線性波長轉換直接將波長移至設計的波段，利用電光調制的幫助，在第四章中會闡述如何對於已有的雷射光頻譜進行電光調變，進而達到更窄頻或多光譜尖峰的同調光源。在釹雷射腔內以一個非週期性極化反轉鈮酸鋰晶體來達成兩個波段的腔內光參量振盪且其頻譜可同時做電光調變，在系統泵浦4.7瓦特且在晶體Y方向施加電場時，由頻譜分析儀解析小於0.06奈米(主要受限於該頻譜分析儀最高解析力，並且根據模擬，訊號光應可窄至0.01奈米附近)。有趣的是，模擬的過程中，發現閒置光的頻寬，即使沒有對應的電光調變，但是藉由訊號光的電光調變窄化，也跟著顯著的變窄。對比於一般中紅外光源頻寬較寬(即使普通藉由光參量過程產生的閒置光亦然)，這個架構提供了一個同時窄化近紅外和中紅外光的有效辦法。除了傳統一維或二維光柵狀來組成準相位匹配的空間結構，在第五章也會介紹利用喇叭狀搭配扇形週期在雙稜鏡結構置於釹雷射共振腔內達成同時運行Q調制和連續電光調變腔內光參量產生/振盪器轉換波長的獨特元件架構。在施加電壓在正負七百五十伏特在這特殊元件(D值為1)時，可調變的波長範圍約為七十奈米。雖然製作出來的元件D值僅為0.53，但可電光調變的波長範圍亦有約三十五奈米。而藉由這個獨特元件輻射出來的波長調變區間就在中紅外光的區段。 ;Laser technology has been widely implemented into many fields, such as light communication, bio-medicine, display technology, remote sensing, environmental detection. Compact, multi-functional yet efficient optical devices are desired in many photonics and laser systems and applications. In this dissertation, those requirements can be potentially fulfilled by introduced one-dimensional (1D) or two-dimensional (2D) periodic or aperiodic photonic devices with the high integration of the electro-optical (EO) modulation, the nonlinear wavelength conversion, and the laser gain medium doping. In the very first two chapters, the research motivation and background will be introduced, and the theories of the electro-optic effect of lithium niobate crystal will be basically discussed. In the chapter three, 2D nonlinear phtonic devices are demonstrated to perform laser Q-switch as well as optical parametric gain medium (OPGM) simultaneously. Continuous wavelength tuning of the IOPO signal in the eye-safe region via the temperature control of the 2D PPLN and 2D Nd:MgO:PPLN were also achieved. The introduction and description of the desired active laser devices designed by aperiodic optic superlattice (AOS) and optimized by simulated annealing (SA) method will follow. The 1D-/ 2D-NPC based on the developed algorithm with multiple functionalities, including EO Q-switch, EO polarization mode converter (PMC), intracavity second-harmonic generator (ISHG), intracavity sum frequency generator (ISFG), intracavity optical parametric oscillator (IOPO), for variety applications are be reported. In the chapter four, we demonstrate an electro-optically spectrum tailorable IOPO basked on a novel APPLN device working simultaneously as an multi- wavelength OPDC and an EO PMC (an active wavelength filter) in a diode-pumped Nd:YVO$_4$ laser. A calculation model has been developed to construct the domain structure of the APPLN and to predict the output spectrum of the built EOST IOPO. The measured output signal spectrum of the EOST IOPO producing two narrowed spectral peaks when operated at E$_y$= 150 V/mm at a diode pump power of 4.7 W. Both spectral bandwidths of the two signals were below 0.06 nm (which reaches the resolution limit of the OSA). According to the simulation, not only the signal spectrum but also the idler spectrum can be electro-optically tailored, leading the system to generate narrowed multiple signals and idlers at near- and mid-IR regions, respectively. Other than forming a spatial structure by the conventional 1D or 2D grating, in the fifth chapter, we design and construct a unique horn-shaped-fan-out-double-prism domain (or ramped duty-cycle) PPLN crystal that integrates the functionalities of an EO beam deflector and an OPDC to work in a compact diode-pumped, 1064-nm Nd:YVO$_4$ laser to realize an efficient EO tunable pulsed IOPG/IOPO. The horn-shaped-fan-out-DPD PPLN crystal can work as an EO beam deflector with a normalized deflection sensitivity of 0.36$^o$/kV-cm and can simultaneously work as a QPM wavelength converter for performing the 1064 nm pumped optical parametric down converter in a range of 1863 - 1929 (by applying -750 V to 750 V). The signal wavelength tuning of the IOPG/IOPO via the electric-field control of the horn-shaped-fan-out-DPD PPLN could be demonstrated in the Mid-IR band.
Appears in Collections:	[Graduate Institute of Optics and Photonics] Electronic Thesis & Dissertation

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