Method and apparatus for electric field measurement based on a levitated particle

A method for electric field measurement based on a levitated particle includes steps of (1) capturing a particle and levitating the captured particle; (2) adjusting a quantity of electric charge carried by the levitated particle; (3) measuring a charge number N of the levitated particle; (4) disposing the levitated particle in an electric field to be measured, measuring a displacement power spectral density Svxel of the levitated particle under the electric field and obtaining an electric field force Fel; and (5) according to a formula of E=Fel/Nqe, obtaining an electric field intensity E. An apparatus for electric field measurement based on a levitated particle includes a high-voltage DC (direct current) power supply, two bare wire electrodes, a vacuum chamber, a trapping laser, an objective lens, a pair of parallel electrodes, a collective lens, a quadrant photodetector, a lock-in amplifier, a signal generator and a power amplifier.