Design strategy for broadband or dual-band ultrathin imaging system

Using reflective multiple-fold approach can reduce bulk and weight compared with large high-quality optical systems and improved resolution and light collection compared with miniature conventional systems. Air-spaced concentric multi-reflection (ACMR) systems, where two reflective surfaces surround a hollow cavity, are useful for extended focal distance, achromatic aberration, useful for inexpensive, lightweight IR imagers and may lead to convenient designs for broadband or dual-band imagers. Design a camera, which spectral response 2-12 μm, with a total thickness of 30 mm, 130 mm effective focal length, ±4.2 FOV, 0.022 mrad resolution and 68 mm effective aperture, 96 mm outer aperture. Application can fit into the hull or wing of a micro-UAV aircraft, which weight and thickness are tightly constrained, for long range surveillance.