隨著微型光導與光子學技術的蓬勃發展，具備波長可調控特性的微型雷射在光通訊、生物感測與全彩顯示等領域展現出巨大的應用潛力。其中，膽固醇液晶（CLC）因具備自組裝光子晶體結構與獨特的選擇性布拉格反射特性，成為實現低閾值、寬頻可調控有機微腔雷射的理想材料平台。然而，傳統液晶雷射往往受限於高驅動電壓、狹窄的調控範圍，以及對外部大型溫控模組的強烈依賴，嚴重限制其在可攜式與高度整合型光電元件中的實際應用。因此，開發具備低電壓驅動、寬頻調控且易於整合的新型液晶雷射結構實為當前極具重要性之課題。本論文成功研製一種基於摻混層列型液晶之低電壓、寬頻可調控膽固醇液晶三明治結構雷射元件。為解決傳統單層液晶雷射中增益介質與光子能隙結構相互干擾的挑戰，本研究採用三明治結構之幾何微腔設計，將兩側由膽固醇液晶複合材料組成之分佈式布拉格反射鏡，與中間摻雜雷射染料之向列型液晶增益層進行空間獨立分隔。此外，藉由摻混具備特殊相轉變特性之層列型液晶10CB，成功將複合材料之層列相至膽固醇相相變溫度降低至28 °C附近，有效克服傳統膽固醇液晶熱調控範圍狹窄且需仰賴大型溫控設備之限制。
在元件驅動機制方面，本研究結合氧化銦錫（ITO）鍍膜玻璃之電致發熱特性，僅需施加微幅低直流電壓（2.15 V～2.50 V），即可藉由焦耳熱引致螺距縮短，驅動兩側膽固醇液晶反射鏡之光子能隙於可見光波段（625 nm～555 nm）進行顯著藍移。在雷射性能表現上，針對綠光（532 nm）與藍光（450 nm）脈衝雷射激發源，本研究分別設計並製備對應之三明治結構樣品Sample A與Sample B。實驗結果顯示，藉由調控兩側分佈式布拉格反射鏡之直流發熱電壓（2.00 V～3.10 V），Sample A 與 Sample B 分別成功實現涵蓋625 nm～555 nm（波長調控範圍達70 nm）與620 nm～490 nm（波長調控範圍達130 nm）之寬頻雷射波長調控。此外，透過對中間增益層施加微幅交流電壓，調控液晶導軸之傾角與等效雙折射率Δneff，可進一步達成缺陷模態雷射波長之精細微調。本研究成果展現了兼具低驅動電壓與寬頻可調控特性之液晶微腔雷射，可作為後續開發微型化、寬頻可調液晶雷射元件之參考。

This thesis presents a low-voltage, broadband-tunable cholesteric liquid crystal (CLC) composite laser based on a symmetric sandwich microcavity. The device spatially separates two CLC composite distributed Bragg reflectors (DBRs) from a central dye-doped nematic liquid crystal (DDNLC) gain layer, thereby allowing the reflectors and gain medium to be controlled independently. A smectic LC, 10CB, was incorporated into an E7/R811 mixture to lower the smectic-to-cholesteric phase-transition temperature to 28 °C. Joule heating generated by indium tin oxide (ITO)-coated substrates enabled large photonic-bandgap shifts at low direct-current (DC) voltages. Two devices were fabricated for excitation at 532 and 450 nm. As the voltage applied to the outer DBRs increased, Sample A was tuned from 625 to 555 nm, while Sample B was tuned from 620 to 490 nm, corresponding to tuning ranges of 70 and 130 nm, respectively. Applying a small alternating-current (AC) voltage to the central DDNLC layer further shifted the emission from approximately 587 to 584.5 nm by changing its effective refractive index. The lasing peaks occurred within the CLC photonic bandgap and matched the CLC helix's circular handedness, supporting their assignment to defect-mode lasing. These results demonstrate a compact, low-power approach to coarse and fine electrical control of laser emission across a broad portion of the visible spectrum.

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