本論文是利用氣相傳輸平衡法(VTE)將由柴式長晶法所生長的共熔配比之摻釕鈮酸鋰(Ru:CLN)轉換成近化學計量配比之摻釕鈮酸鋰(Ru:nSLN)晶體。當VTE處理時間增長時，會使晶體中的[Li]/[Nb] 比值增加，造成UV/VIS 吸收邊往紫外光偏移，並使得位於530nm波長下的吸收係數下降。而OH-吸收光譜會因為 [Li]/[Nb]比值的增加，使位在3482cm-1 波數的寬吸收峰漸漸地衰減，同時也使得位在3466cm-1 波數的吸收峰漸漸地增強，並且隨著VTE 反應時間增長時，此吸收峰變的較尖端。當VTE 處理時間達到200小時，則可以得到近化學計量配比摻釕鈮酸鋰晶體。藉由使用532nm 雷射波長的雙波耦合實驗可以得知近化學計量配比摻釕鈮酸鋰有良婕的光學性質，並與共熔配比摻釕鈮酸鋰晶體的比較之下，擁有較大的指數增益係數、較低的繞射效率、較快的響應時間、較高的光敏感性、較大的動態範圍與較小的黑暗衰減時間常數。 In this thesis, Ruthenium (Ru)-doped near-stoichiometric lithium niobate crystals (Ru:nSLN) were prepared by the Vapor Transport Equilibration (VTE) method from Ru-doped congruent lithium niobate grown using the Czochralski method. Increasing the duration time of the VTE treatment would cause the ratio of [Li]/[Nb] in the crystal to increase, which in turn caused that the absorption edges to shift to violet, and the absorption coefficient in the UV/VIS absorption spectra at 530nm to decrease. The broad band in the OH- absorption spectra located at 3482 cm-1 also gradually decreased while another band located at 3466cm-1 gradually increased. The shape became sharper as the VTE treatment time increased. When the VTE treatment time reached 200 hours, Ru-doped near-stoichiometric lithium niobate crystals were obtained. Two-beam coupling examination with a 532nm laser showed that the Ru-doped near-stoichiometric lithium niobate compares with Ru-doped congruent lithium niobate crystals had a larger exponential gain coefficient, lower diffraction efficiency, faster response time, higher sensitivity, higher dynamic range and smaller dark decay time constant than did the Ru-doped congruent lithium niobate crystals.