Fiber optical tweezers benefit from compact structures and compatibility with fiber optic technology, however, trapping of nano-objects are rarely demonstrated. Here, we predict stable optical trapping of a 30 nm polystyrene particle using an all-dielectric coaxial optical fiber supporting an axisymmetric TEM-like mode. We demonstrate, via comprehensive finite-difference time-domain simulations, that the trapping behavior arises from a significant shift of the fiber-end-fire radiation directivity originated from the nanoparticle-induced symmetry breaking, rather than the gradient force which assumes an invariant optical field. Fabrication of the fiber involved is entirely feasible with existing techniques, such as thermal-drawn and electrospinning, and therefore can be mass-produced.

光纤镊子受益于紧凑的结构和与光纤技术的兼容性，然而，纳米物体的捕获很少被证明。在这里，我们使用支持轴对称 TEM 类模式的全介电同轴光纤预测 30 nm 聚苯乙烯粒子的稳定光学俘获。我们通过全面的有限差分时域模拟证明，捕获行为源于纳米粒子引起的对称性破坏引起的光纤端射辐射方向性的显着偏移，而不是假设光学不变的梯度力场地。所涉及的纤维的制造使用现有技术（例如热拉伸和静电纺丝）完全可行，因此可以批量生产。