Fig. 1. Optical levitation system based on one traditional desktop laser from the group of Pesce^[18] (M, 45° mirror; L, lens; F, filter; P, polarizer).

Fig. 2. One edge emission laser (EEL) diode encapsulated in a transistor outline (TO). (a) Physical diagram of an EEL; (b) schematic diagram of optical field distribution.

Fig. 3. Distributions of light intensity across the cross section of the elliptical Gaussian beam along the direction of propagation.

Fig. 4. Variation of transverse light intensity of the elliptical Gaussian beam along the direction of propagation.

Fig. 5. Optical field distribution of the laser diode in the experiment before focusing.

Fig. 6. Schematic of the optical system.

Fig. 7. Optical system. (a) Assembly drawing; (b) photograph of the optical system.

Fig. 8. Optical field distribution of the laser diode in the experiment after beams are focused.

Fig. 9. Manufacturing process of the MEMS particles cavity.

Fig. 10. Photograph of the MEMS particles cavity.

Fig. 11. Optical levitation system. (a) Schematic diagram; (b) photograph of the miniature optical levitation system.

Fig. 12. Experimental test setup of the optical levitation system. (a) Diagram of the optical path; (b) photograph of the experimental system.

Fig. 13. Trapping process of one SiO₂ particle. (a) Silica is stably trapped; (b), (c) processes of moving the micro-particles cavity to the lower right.

Fig. 14. Measurement results of the dielectric particle displacement by the QPD. Displacement along (a) long axis and (b) short axis of the elliptical beam.

Fig. 15. Frequency spectrum distributions of the X and Y axes of the QPD (a),(b) when no dielectric particle is trapped and (c), (d) when one dielectric particle is trapped.