| 摘要: | 本論文利用模擬退火法設計出藉由施加單段電光調制而得到1064.5nm & 1342.33nm雙波長的選頻，有別於其他使用機械式的波長與波長之間選頻的切換本實驗利用電光調制系統快速的切換波長選擇輸出，切換的時間遠遠小於它們，
本論文還利用單段電光分別主動式Q調制1064.5nm & 1342.33nm雙波長進而得到非相位匹配(non-phase matching)的綠光脈衝雷射與紅光脈衝雷射，還可以利用雙波長同時Q調制來達到和頻的作用進而輸出非相位匹配(non-phase matching)593nm的橘黃光脈衝雷射之非週期性極化反轉鈮酸鋰晶體。
本論文也實際經過黃光微影製程，並利用高電場極化反轉製程做出電光非週期性極化反轉鈮酸鋰晶體，最後進行端面拋光以及鍍上端面的抗反射膜。
在實際量測上本實驗對電光非週期性鈮酸鋰極化轉鈮酸鋰晶體施加三種不同的Y方向電場來達到單段或雙波長輸出，經由三面共軸線性的共振鏡所組成的Nd:YVO4雷射系統中，調整M2 & M3的距離使兩波長增益相同，在未施加電場下(0V/mm)，可以同時輸出波長1064.5nm & 1342.33nm之最高能量cw雷射；在施加電場267V/mm下，可以只輸出波長1064.5nm之最高能量cw雷射；在施加895V/mm，可以只輸出波長1342.33nm之cw雷射。
另外我們還對電場做了一個容忍度的量測，在施加DC電場244V/mm到285V/mm，總共42V/mm的容忍度都可以只單一輸出1064.5nm訊號光cw雷射光，而在施加DC電場884V/mm到916V/mm，總共33V/mm的容忍度都可以只單一輸出1342.33nm訊號光cw雷射光。
另外用電光非週期性鈮酸鋰極化轉鈮酸鋰晶體施加三種不同的Q調制系統來達到五種不同波長的雷射脈衝雷射光產生，其一為在電場267V/mm & 685V/mm的Q開關快速切換之下可產生1064.5nm脈衝雷射光，其最窄的脈衝寬度為約為9.6171ns，其腔內的尖峰功率約為18580瓦與經由鈮酸鋰晶體所產生的非相位匹配(non-phase matching)之二倍頻532nm綠光脈衝雷射光，綠光最窄的脈衝寬度為約為8.7368ns，其尖峰功率約為30.8瓦。
其二為在電場895V/mm & 685V/mm的Q開關快速切換之下可產生1342.33nm脈衝雷射光，其最窄的脈衝寬度為約為25.4740ns，其腔內的尖峰功率約為6332瓦與經由鈮酸鋰晶體所產生的非相位匹配(non-phase matching)之二倍頻671nm紅光脈衝雷射光，紅光最窄的脈衝寬度為約為15.0374ns，其尖峰功率約為9.7瓦。
其三為在電場0V/mm & 685V/mm的Q開關快速切換之下可產生1064.5nm & 1342.33nm脈衝雷射光，並經過鈮酸鋰晶體之和頻機制而得到的非相位匹配(non-phase matching)593nm脈衝雷射橘黃光，593nm橘黃光最窄的脈衝寬度為約為8.0198ns，其尖峰功率約為74.19瓦。
在未來可選擇兩個波長距離相對於較近的波長，例如使用增益晶體為Nd:YLF的雷射系統(受激輻射頻譜為1047nm & 1053nm)，並且又能用在電光調制下分開並且選頻，這將會是一大進步。
;In this thesis, we demonstrated an aperiodically poled lithium niobate (APPLN) crystal, which designed by the simulated annealing method for simultaneously being an electro-optic (EO) laser-line switch and an EO Q-switch in a dual-wavelength Nd:YVO4 laser. The demonstrated system can realize dual-wavelength selection of both or either one of the 1064.5nm and 1342.33nm laser lines simply by EO tuning (via voltage switching), which features ultra-fast switching speed in contsrast to those using slow mechanical or thermal tuning mechanisms.
In this study, we first successfully achieved wavelength selection via EO tuning in a cw dual-wavelength 1064.5nm and 1342.33nm laser; both laser lines can be produced when no external electric field is applied to the APPLN device, while only the 1064.5nm laser line and only the 1342.33nm laser line can be produced when electric fields of 267V/mm and 895V/mm are applied to the APPLN, respectively, with electric-field tuning tolerances of ~42V/mm and ~33V/mm, respectively.
Moreover, when the novel APPLN device in the dual-wavelength Nd:YVO4 laser system is switched between 267V/mm and 685V/mm electric fields at a repetition rate of 1kHz, we can obtain pulsed 1064 nm laser generation (~18.5kW peak power), accompanying with non-phase-matched second-harmonic (SH) 532 nm green laser generation (~30 W peak power). When the laser system is switched between 895V/mm and 685V/mm electric fields at a repetition rate of 1kHz, we can obtain pulsed 1342 nm laser generation (~6.3kW peak power), accompanying with non-phase-matched SH 671 nm red laser generation (~9.7 W peak power). Moreover, when the laser system is switched between 0V/mm and 685V/mm electric fields at a repetition rate of 1kHz, we can obtain pulsed 1064 and 1342 nm dual-line laser generation, accompanying with non-phase-matched sum-frequency 593 nm orange laser generation (~74 W peak power). The novel Nd:YVO4 laser system using an APPLN crystal as simultaneously an EO laser-line switch and an EO Q-switch can thus produce pulsed 1064 nm, 1342 nm, 593 nm orange, 532 nm green, and 671 nm red generations simply by EO tuning. |
