两种单光纤光镊捕获效果的数值仿真与实验研究

采用一种基于时域有限差分(FDTD)的数值算法,仿真计算了抛物线形和大锥角形两种新型单光纤光镊的出射光场,并在稳态场下通过对麦克斯韦应力张量积分求得介质球在两种光场中受到的光阱力,得到大锥角型光纤端产生的光阱力较大的结论;讨论了不同介质球大小、折射率,光纤探针形状对光阱力的影响.在实验中这两种光纤探针都实现了对水中酵母菌细胞的捕获,且采用流体力学法对抛物线形和大锥角形二种新型单光纤光镊产生的光阱力进行了标定.结果表明:基于FDTD数值仿真方法计算受力与实验结果一致,并且这种计算光纤光镊产生的光阱力的方法简单.适用;且抛物线形和大锥角形光纤探头都具备构成单光纤光镊的条件.

Numerical Simulation and Experiments of Two Fiber Optical Tweezers

The finite difference time domain(FDTD) method was used to calculate the output optical fields of parabolic and large angle single-fiber optical tweezers.The transverse and axial trapping forces were then obtained by integrating the Maxwell stress tensor in stable state.Compared with the parabolic fiber optical probe,the optical force of the large angle fiber probe is lager.Meanwhile,the influences of sizes and diffractive indexes of microscopic particles and profile of fiber probe on the optical force were...