光鉗技術為生醫光電及材料科學開啟嶄新的大門，一般渦流光束光鉗(Optical vortex tweezer)是由空間光調制器(Spatial light modulation, SLM)產生，但空間光產生器有單價高，無法承受高強度雷射的缺點，且SLM利用全像術繞射產生渦流光束效率偏低(只有約60%)。
本研究利用摻雜染料液晶(dye-doped liquid crystal, DDLC)經光配向(Photoalignment)產生q-plate高效率調制雷射光元件(效率可達80%)，利用此元件產生渦流光束，並研究渦流光束抓取微米等級微粒，並比較不同q值的渦流光束對抓取微粒有何影響。
研究共分為三大部分，首先利用光配向技術對摻雜染料液晶(DDLC)進行配向產生q-plate液晶樣品，利用干涉儀找到相位奇點來證明q-plate確實能將高斯光束(Gaussian beam)轉換成渦流光束 (Vortex beam)，並探討不同q值產生的vortex在平面波以及球面波下的干涉條紋有何不同。第二部分為架設光鉗系統，研究光強度對微粒抓取有何影響，本研究為了觀察微粒的抓取行為，採用不可見光波段1064 nm 雷射作為製造渦流光束光鉗光源。第三部分結合q-plate及光鉗系統，觀察不同q值的渦流光束對微粒抓取的受力以及穩定度有何影響，研究中採用與細胞相同尺度微米等級的微粒，分別為Whitehouse 3 μm SiO_2 微粒，以及Sigma 5 μm聚苯乙烯微粒(Polystyrene ball)，比較不同大小以及不同折射率對抓取微粒的受力及穩定度有何影響。

The thesis is divided into three parts. Firstly, a q-plate is produced based on dye-doped liquid crystal (DDLC) cell using the photoalignment technique. Then the q-plate is used to produce a vortex beam verified using a Michelson’s interferometer. In the second part, we construct an optical tweezers system. Finally, the trapping of the micron-sized particles with different refractive index is investigated using the vortex-beam optical tweezers system. The results show that the manipulation of particles of the vortex-beam optical tweezers is significantly affected by the q-value of a q-plate. The smaller the q-value is, the longer distance of the particle can be moved and trapped by the tweezers. Also, regardless of the refractive index, the particle is trapped in a similar location by the vortex beam.

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