Super-oscillatory pupil filter enabling mid-wave infrared super-resolution system

Current designs of optical super-oscillatory devices predominantly focus on the visible and near-infrared bands. However, for the detection of specific targets, the mid-wave infrared (MWIR) band also contains abundant valuable information. Applying optical superoscillatory technology to the field of infrared detection is of significant research interest. This technology can overcome the resolution limitations inherent in conventional infrared focal-plane imaging systems, thereby enabling the detection and early warning of small infrared targets within localized fields of view. This paper proposes what we believe to be a novel approach for achieving far-field optical super-resolution in MWIR systems by employing an amplitude-type pupil filter. Based on this approach, a prototype of a long-focal-length MWIR imaging optical system is designed and fabricated. This prototype demonstrated a super-resolution factor of 1.195 at the focal plane. Both simulation results and proof-of-concept experiments verify the feasibility and effectiveness of the proposed MWIR super-oscillatory far-field super-resolution imaging scheme.