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 super-oscillatory 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.