This invention discloses a
wavelength division
multiplexing (WDM)
trapping device and a method for measuring extremely weak forces in a single-beam vacuum optical trap. A
fiber laser emits a
laser beam, which passes sequentially along the
fiber through a
fiber acousto-optic modulator, a fiber
beam splitter, and a 1064nm fiber
collimator to obtain beam A. Beam A is transmitted through a dichroic mirror into a vacuum cavity,
trapping and detecting micro / nano particles. Beams B, C, and D, obtained through multiple fiber
beam splitters, a PPLN
waveguide frequency doubling module, a fiber electro-optic modulator, and a 532nm fiber
collimator, sequentially enter the vacuum cavity to triaxially cool the micro / nano particles in a vacuum environment. At this point, the micro / nano particles are in a
stable state. A
voltage is applied to the
electrode plate, reducing the intensity of beam A, ultimately achieving a balance between
electric field force and gravity. The
electric field force is then used as the measurement value for the gravity of the micro / nano particles. This invention employs a
wavelength division
multiplexing method, achieving triaxial cooling,
trapping, and detection with only one
light source, and using
optical fiber to replace most optical components, resulting in greater integration.