Abstract:
An imaging optical system and a three-dimensional (3D) image acquisition apparatus which includes the imaging optical system are provided. The imaging optical system includes an object lens configured to transmit light; first and second image sensors having different sizes from each other; a beamsplitter on which the light transmitted by the object lens is incident, the beamsplitter being configured to split the light incident thereon into light of a first wavelength band and light of a second wavelength band, and to direct the light of the first wavelength band to the first image sensor and the light of the second wavelength band to the second image sensor; and at least one optical element, disposed between the beamsplitter and the second image sensor, configured to reduce an image that is incident on the second image sensor, the optical element including at least one of a Fresnel lens and a diffractive optical element.