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.
