以串級式電光週期性晶格極化反轉鈮酸鋰達成三波長主動式Q-調制Nd:YVO4雷射;Pulsed orange, green, and red laser generations in an actively Q-switched Nd:YVO4 laser using cascaded electro-optic PPLN Q-switches

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/7085

Title:	以串級式電光週期性晶格極化反轉鈮酸鋰達成三波長主動式Q-調制Nd:YVO4雷射;Pulsed orange, green, and red laser generations in an actively Q-switched Nd:YVO4 laser using cascaded electro-optic PPLN Q-switches
Authors:	張煒堃;Wei-Kun Chang
Contributors:	光電科學研究所
Keywords:	Q調制;鈮酸鋰;電光;週期性晶格極化反轉;Q-switch;PPLN;EO;Nd:YVO4
Date:	2009-07-10
Issue Date:	2009-09-22 10:36:58 (UTC+8)
Publisher:	國立中央大學圖書館
Abstract:	利用摻雜釹的固態雷射以腔內倍頻的方法可以有效的得到藍、綠和紅光。但光譜在550 到650-nm 之黃橘光雷射卻相對稀少且低效率；而欲以倍頻方式產生也因無相對之高效率紅外基頻雷射而不可得。因此利用對摻雜釹的固態雷射其兩個重要的發射譜線4F3/2 – 4I11/2 (?~1.06 ?m) 及 4F3/2 - 4F13/2 (?~1.3 ?m)以腔內或腔外和頻的方式產生黃橘光的雷射已成為重要的方法。黃橘光雷射源特別在生物醫藥、光達、天文及軍事等應用上受到重視。而脈衝式黃橘光雷射更可因其高重複率與高功率的特性而提供更廣大的應用。本論文創新性提出以單塊串級式電光週期性晶格極化反轉鈮酸鋰 (periodically poled lithium niobate; PPLN)來分別Q-調制Nd:YVO4之1064-nm 與1342-nm 雷射譜線並同時調節該兩譜線之損益比例及Q-開關時間差以達成最佳之雙波長脈衝及黃橘光和頻產生。此法將比傳統上使用單一Q-開關系統產生出更高效率之脈衝黃橘光雷射源。在單塊晶體3-cm 的長度之下，當Q 調制訊號只輸入任一Q-開關時，除了可得對應之共振雷射脈衝，還有藉由鈮酸鋰晶體非線性性質產生非相位匹配產生的倍頻脈衝。在約五瓦特的泵浦下，1-kHz 的重複開關頻率，可得1342-nm 最短脈寬26.96-ns 和尖峰功率14 千瓦特以及671-nm 最短脈寬15.2-ns 和尖峰功率8.6 瓦特;抑或得到1064-nm 最短脈寬14.95-ns 和尖峰功率18.5 千瓦特以及532-nm 最短脈寬9.26-ns 和尖峰功率20.6 瓦特。再利用BIBO 腔內和頻晶體在雙Q-開關之Q 調制訊號延遲25-ns 時，得到和頻593-nm 最短脈寬5.83-ns 和尖峰功率140 瓦特。Intracavity frequency doubling in an Nd-laser system has become one of the most efficient methods of producing blue, green, and red coherent lights. However, no practical laser sources yet currently available in the yellow-orange (570-620-nm) spectral region, nor applicable fundamental infrared lasers for performing efficient frequency doubling to the region. Sum frequency generation (SFG) of two emission lines from transitions 4F3/2 – 4I11/2 (?1~1.06 ?m) and 4F3/2 - 4F13/2 (?2~1.3 ?m) of Nd-lasers has become an important approach of generating coherent radiation in the yellow-orange spectral region. Compact, high-repetition-rate pulsed visible coherent light sources are attractive for many applications such as bio-medicine, remote-sensing, astronomy, and military. We achieved in a collinear three-mirror dual-wavelength Nd:YVO4 laser system using two monolithically cascade electro-optic (EO) periodically poled lithium niobate (PPLN) Q-switches to separately control the Q-switching operation of the two wavelengths to optimize the temporal overlap between them for efficient pulsed intracavity sum-frequency generation. With this novel system, we can generate 5 high peak-power and high repetition-rate lasers radiating at Nd:YVO4 1064- and 1342-nm lines and their non-phase-matched SHG 532- and 671-nm light and their phase-matched SFG 593-nm light via the manipulation of the Q-switching operations of the 3-cm bulk EO PPLN Q switches. We found a pulse build-up delay time of ~25 ns between the two pump wavelengths is required for achieving the best SFG efficiency in our system. When the system is operated at a repetition rate of 1 kHz and a pump power of ~5W, we obtained pulsed orange (593 nm), green (532 nm), and red (671 nm) generations with peak powers of 140, 20.6, and 8.6 W, respectively.
Appears in Collections:	[Graduate Institute of Optics and Photonics] Electronic Thesis & Dissertation

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