Optical design of a multi-channel, multi-resolution imaging system

Abstract

This paper presents the design of a multi-channel imaging system which has a different angular resolution and field of view in the different channels. Our aim was to design a multi-resolution imaging system that can be fabricated at wafer scale to obtain a compact and low cost imaging device. This imaging system is able to resolve fine details of a small region of interest and control the surrounding region at the same time. An interesting aspect of such a multi-channel, multi-resolution imaging system is that it allows to implement different image processing algorithms at different segments of the image sensor for several imaging functionalities. We have designed an imaging system that has three optical channels where each optical channel consists of four aspheric lens surfaces. The design was analyzed and optimized with CODE V optical design software. The three optical channels share one image sensor which has 1440×960 pixels and a pixel size of 10μm. The first optical channel has the highest angular resolution (0.0096°) and smallest field-of- view (2×3.5°).The third optical channel has the highest field of view (2×40°) and lowest angular resolution (0.078°). The second optical channel has intermediate imaging properties between the first and the third optical channels; however, it has the same image sensor segment size as the first channel. All the three optical channels have diffraction limited performance ensuring good overall image quality.