Photonics-enhanced smart imaging systems

Abstract

We discuss different photonics-enhanced multichannel multiresolution imaging systems in which the different channels have different imaging properties, namely a different FOV and angular resolution, over different areas of an image sensor. This could allow different image processing algorithms to be implemented to process the different images. A basic threechannel multiresolution imaging system was designed at 587.6 nm where each of the three channels consist of four aspherical lens surfaces. These lenses have been fabricated in PMMA through ultra-precision diamond tooling and afterwards assembled with aperture stops, baffles and a commercial CMOS sensor. To reduce the influence of chromatic aberrations, hybrid lenses, which contain diffractive surfaces on top of refractive ones, have been included within the previous designs of the three channels. These hybrid lenses have also been fabricated through ultra-precision diamond tooling, assembled and verified in an experimental demonstration. The three channels with hybrid lenses show better image quality (both in the simulation and experiment) compared to the purely refractive three channel design. Because of a limited depth of field of the aforementioned multichannel multiresolution imaging systems, a voltage tunable lens has been integrated in the first channel to extend the depth of field of the overall system. The refocusing capability has significantly improved the depth of field of the system and ranged from 0.25 m to infinity compared to 9 m to infinity for the aforementioned basic three-channel multiresolution imaging system.