从实验和理论两方面 ,讨论了在光镊系统中 ,光放大倍数在 5 0 0— 10 0 0倍、间隔为 10 0倍的范围内 ,对四象限探测器位移测量信号的幅值及其线性度的影响 .实验结果与理论结果符合很好 ,得出相同的结论 :当微粒的影像半径约为四象限探测器探头半径 (5 0— 6 0 ) %时 ,可以得到幅值大、线性好的输出信号 . From two aspects of experiment and theory, the amplitude of displacement measurement signal of four-quadrant detector in the optical tweezers system is discussed in the range of light magnification of 500-1000 times and the interval of 100 times, and its Linearity.Experimental results agree well with the theoretical results and come to the same conclusion: when the radius of the particle image is about 50-60% of the radius of the four-quadrant detector, we can get a large amplitude, linear Good output signal.