分别从理论和实验上分析了光纤表面倏逝场强度的分布(z=10 nm, 100 nm, 500 nm,1 000 nm), 研究了微米级光纤光镊对微球的操纵。实验中把直径为125 μm的普通单模光纤拉制成锥腰直径为2 μm的锥形光纤。当光纤通光时, 在光纤锥区倏逝场的作用下, 直径3 μm的聚苯乙烯微球保持平衡状态, 并且光纤附近的微球被吸引到光纤表面, 以5.3 μm /s的速度沿着光束的传播方向运动。这个实验不仅实现了对微球的成功捕获, 而且验证了光纤光镊的力学作用。光纤光镊对微球的无接触、无损伤操纵, 将在生物传感领域有潜在的应用。

The evanescent field intensity distribution of the fiber was analyzed both theoretically and experimentally(z=10 nm, 100 nm, 500 nm,1 000 nm), and the manipulation of micron fiber optical tweezers for microspheres was studied in experiment. In the experiment, a single-mode optical fiber with a diameter of 125 μm was transformed into a tapered fiber with a 2 μm diameter at the minimum waist. When the laser light was launched into the fiber, due to the evanescent field of the tapered fiber, the polystyrene microspheres with a diameter of 3 μm could keep balanced state, and the nearby microspheres were attracted onto the fiber surface and rolled at the speed of 5.3 μm/s in the direction of light propagation. This experiment traps the microspheres and verifies the mechanical effect of the fiber optical tweezers. The non-contact, non-destructive manipulation of fiber optical tweezers for microspheres has potential applications in the field of biosensors.