We theoretically and experimentally study the propagation characteristics of the circular Airy beam (CAB) when its first few light rings are blocked. It is shown that the focus position of the blocked CAB will remain the same, and its abruptly autofocusing property will be enhanced. Since the maximum focal intensity almost remains the same when the first ring is blocked, a better result of abruptly autofocusing property can be obtained when only the first ring is eliminated. Compared with the common CAB with a same hollow region, the intensity of the blocked CAB will focus at a different position and the intensity will be increased much larger than the common CAB.

• Allan variance is introduced to evaluate the stability of the optically optomechanical system for actual force detection performance. • The system obtains a force detection sensitivity of 4.34 zN/Hz^1/2 at 7.9 × 10⁻⁹ mbar under parametric feedback cooling, which is the best force sensitivity in a levitated optomechanical system so far. • The optimal measurement time is 2751 s, and the force detection resolution corresponding to this time scale is approximately 166.40 ± 55.48 yN, which is also the best force resolution in a levitated optomechanical system so far.

We found a new type of noncircular symmetrical Airy beam called an elliptical Airy beam (EAB). Using a simple single-pixel checkerboard hologram method, we achieved the EAB in an experiment. We observed its unique property of double focusing and the ability of the energy to flow towards the endpoints of the long axis during propagation. These particular properties will have some potential applications.

In this work, the radiation force on a Rayleigh dielectric particle induced by the partially coherent circular Airy beam (PCCAB) is investigated. Our numerical results show that the PCCAB can be used to trap and manipulate particles. The radiation force distribution and trapping stability have been analyzed under different coherent lengths. It is found that, with the increase of the spatial coherent length, the radiation force is increased and the particle can be stably trapped at more points. Therefore, the radiation force as well as the depth of potential well can be effectively modulated by controlling the spatial coherent length in optical micromanipulation. The trapping properties of PCCAB have also been studied under other different parameters, including the scale factor and initial radius.

We report on the simultaneous observation from four directions of the fluorescence of single $^{87}$Rb atoms trapped at the common focus of four high numerical aperture ($\textrm {NA}=0.5$) aspheric lenses. We use an interferometrically-guided pick-and-place technique to precisely and stably position the lenses along the four cardinal directions with their foci at a single central point. The geometry gives right angle access to a single quantum emitter, and will enable new trapping, excitation, and collection methods. The fluorescence signals indicate both sub-Poissonian atom number statistics and photon anti-bunching, showing suitability for cold atom quantum optics.

A dual-fiber optical trap system to trap and rotate a borosilicate microsphere has been proposed and experimentally demonstrated. The trapping system can be used as a probe to measure environmental parameters, such as torque, force, and viscosity of the surrounding medium. Under various conditions with different fiber misalignments, optical power, and fiber separation, the trapped sphere will exhibit three motion profiles including random oscillation, round rotation, and abnormal rotation. The power spectrum analysis method is used to measure rotation rates up to 385 Hz, which can be further increased by increasing laser power. In addition, simulation and experiment show consistent results in rotation rates and motion trajectory, which verifies the validity and accuracy of dynamic analysis.