Fig.1

Schematic diagram of the experimental setup for a movable one-dimensional optical potential well"

Fig.2

Phase plates, optical intensity distributions and optical phase distribution information for the focused beam"

Fig.3

Light intensity distribution of a focused Gaussian beam near the focal plane along the beam propagation direction ($z\text{-}$direction) at different focal lengths"

Fig.4

Light intensity distribution near the focal plane of a focused Gaussian beam"

Fig.5

Relationship between the light intensity maximum and focal length of a focused Gaussian beam at different focal lengths"

Fig.6

Relationship between spot size and focal length of a focused Gaussian beam at different focal lengths"

Fig.7

Light intensity distribution of a focused vortex hollow beam in the focal plane at different focal lengths"

Fig.8

Relationship between the light intensity maximum and focal length of a focused vortex hollow beam at different focal lengths"

Fig.9

Relationship between dark spot size and focal length for focused vortex hollow beams at different focal lengths"

Fig.10

Optical potential of polystyrene particles near the focal plane of a focused Gaussian beam"

Fig.11

Gradient force distribution of polystyrene particles near the focal plane of a focused Gaussian beam"

Fig.12

Scattering force distribution of polystyrene particles near the focal plane of a focused Gaussian beam"

Fig.13

Optical potential of water molecules in the focal plane of a focused vortex hollow beam at different focal lengths"

Fig.14

Gradient force distribution of water molecules in the focal plane of a focused vortex hollow beam at different focal lengths"

Fig.15

Scattering force distribution of water molecules in the focal plane of a focused vortex hollow beam at different focal lengths"