Optical design of a simultaneous polarization and multispectral imaging system with a common aperture

ABSTRACT

A polarization and multispectral imaging system enables the acquirement of spatial, polarization and multispectral information of a target simultaneously, thereby improving capability in the detection and identification of low-contrast targets-an increasingly important attribute in many applications. In this work, we propose a simultaneous polarization and multispectral imaging system with a common aperture working at visible, mid-wave infrared and long-wave infrared wavebands. Two dichroic mirrors are used to spectrally split the beams into these three bands. For the visible spectrum, a division-of-focal-plane polarimeter is employed to acquire polarization information. Division-of-aperture-plane polarimeters with a cooled and uncooled detector are exploited in the mid-wave infrared and long-wave infrared, respectively. The division-of-focal-plane and division-of-aperture-plane polarimeters enable our system to achieve real time polarization imaging, which is suitable for moving targets. Simulation results indicate that our proposed system can meet the diverse imaging requirements in each waveband.

KEYWORDS:

• Optical design
• real time imaging
• polarization imaging
• multispectral imaging