Super-oscillation sub-diffraction focusing with emulated atmospheric turbulence

• Published in: Optics and lasers in engineering 2025-01, Vol.184, p.108675, Article 108675
• Main Authors: Yao, Na, Jiao, Jiao, Duan, Jingxuan, Chen, Mo, He, Duanpeng
• Format: Article
• Language: English
• Subjects: Adaptive optics; Diffraction limit; Fourier optics; Super-oscillation; Wavefront aberration
• ISSN: 0143-8166
• DOI: 10.1016/j.optlaseng.2024.108675

•Super-oscilla/on sub-diffrac/on focusing within a 137-element adap/ve op/cs system.•Modest and strong atmospheric turbulence strength simulated.•FWHM ra/o of super-oscilla/on spot and airy spot ∼0.79 /mes. The super-oscillation (SO) phenomena successfully applied to super-resolution optical telescopes have yet to study the existence of atmospheric turbulence (AT). In this paper, we first experimentally investigate the sub-diffraction focusing of the SO light field in the atmospheric-like turbulence. The 137-element adaptive optics (AO) system is utilized to correct the dynamic wavefront aberration produced by the AT and obtain the AO closed-loop RMS of the residual wavefront error ∼λ/15. For a proofed telescope (clear aperture 12 mm and focal length 1000 mm) @λ=632.8 nm, the FWHM of the experimental SO spot under the modest AT (wavefront error RMS ∼0.57λ) is about 0.79 times of the Airy spot compared with the non-AT result of 0.76 times, while the strong AT (wavefront error RMS ∼1.35λ) erases the sub-diffraction focusing effect of the SO field and the average side-lobe intensity increases significantly. This study is promising for super-resolving telescope, synthetic aperture for visible imaging, etc.