Patent ID: 7760356

Claim:
An optical measuring device comprising: a power supply; a container that stores a liquid sample or a gel sample; a pair of electrodes that generate, in a portion of the container, an electric force line distribution in which areas having high electric force line density and areas having low electric force line density are regularly arranged in response to a voltage applied; a dielectrophoresis control unit that controls the generation of a transient diffraction grating using dielectrophoresis of particles in the sample caused by applying the voltage to the pair of electrodes and a variation in the transient diffraction grating due to the diffusion of the particles in the sample according to a variation in the applied voltage; a light source emitting light to the transient diffraction grating; and a plurality of photodetectors detecting diffracted light generated by the transient diffraction grating, wherein the particles are evaluated on the basis of a variation in the intensity of the diffracted light generated by the transient diffraction grating.