本論文主要是探討雷射光鉗的作用，對1μm大小的染色聚苯乙烯微粒之影響，包含染色聚苯乙烯微粒其顏色是否影響雷射光鉗捕捉力、改變雷射波長是否影響雷射光鉗捕捉力，以及微粒在邊界上情形的探討。
　　我們研究了紅色、黃色、藍色、紫色四種1μm染色聚苯乙烯微粒，發現微粒對雷射的吸收率的確會對光鉗垂直捕捉力之Q值造成影響，由數據結果，各色聚苯乙烯微粒對於847.5 nm波長的雷射光其吸收率：紅色聚苯乙烯微粒＞黃色聚苯乙烯微粒＞紫色聚苯乙烯微粒＞藍色聚苯乙烯微粒。而聚苯乙烯微粒也會因為在樣本空間的位置不同，造成光鉗垂直捕捉力的不同，微粒在樣本空間邊界處的所量測到的Q值明顯大於在樣本空間中樣處的量測到的Q值，對紅色微粒、黃色微粒、藍色微粒、紫色微粒而言，其Ｑｍａｘ/Ｑｍｉｎ分別為：（3.41），（4.54和5.64），（9.36和2.09），（2.62和2.03）。另外，受限於儀器，我們只能小幅度的改變雷射波長（844.8 nm～850.5 nm），但從實驗數據中多少也可看出，某些波長的雷射光似乎也較容易被微粒吸收，而不同顏色的微粒對於吸收波段也不盡相同。

　　This thesis studies the color effect on laser tweezers. The influence of the trapping force on 1μm size micro-polystyrene beads includes the color effect by using dyed beads, the wavelength effect by changing the trapping laser temperature and the boundary effect by changing the trapping positions.
　　Using 1μm size red, yellow, blue and violet dyed polystyrene beads, we study the color effect on the trapping efficiency of laser tweezers by comparing the vertical trapping power on the polystyrene beads at different distance to the slides slit. According to the data, the trapping efficiency of the dyed beads on laser wavelength 847.5 nm is : dyed red polystyrene bead > dyed yellow polystyrene bead > dyed blue polystyrene bead > dyed violet polystyrene bead. The results also show the boundary effect for different trapping conditions. The vertical trapping laser power for confining the beads at near both sides of the glasses is larger than that they were in the center of the sample. The ratios Qmax :Qmin (the maximum of trapping efficiency / the minimum of trapping efficiency) for red beads, yellow beads, blue beads, violet beads being in the neighborhood of (3.41),(4.54 and 5.64), (9.36 and 2.09), (2.62 and 2.03). Changing the laser wavelength（844.8 nm～850.5nm）limited by our laser system, we also see the trapping efficiency of laser tweezers changes slightly. The absorption rate of the dyed beads on laser wavelength is larger at certain wavelength, and different color of the dyed beads have different absorption rate.

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