A Light-Field Image Sensor in 180 nm CMOS

This paper presents a CMOS image sensor which captures local incident angle and intensity information from the light it records. The 400×384 pixel array employs 7.5 μm angle-sensitive pixels, which use pairs of local diffraction gratings above a photodiode to detect incident angle. The gratings are implemented with the metal interconnect layers of CMOS manufacturing technology and therefore require no post-processing or external optics. Fabricated in a 180 nm mixed-mode CMOS process, the sensor requires only a single lens to create a light-field image. Using the information contained in a single image, we demonstrate range finding with 2.5 mm precision at 1 m and post-capture refocus on complex visual scenes.