Fig. 1. Concept and application of sparsity and continuity priors in the SC iterative module. (a) Illustrations of sample image priors: absolute sparsity, low-resolution (LR) image representation, relative continuity, and continuity across multi-frame data. The sparsity prior emphasizes the sharp boundaries and distinct structures within the sample, while the continuity prior focuses on maintaining smooth transitions and coherence across both spatial and temporal dimensions. (b) Visualization of the resolution improvement process facilitated by the sparsity and continuity priors. The iterative deconvolution process effectively balances the strengths of both sparsity and continuity to reconstruct a high-resolution image from low-resolution data. (c) Comparison of reconstruction outcomes using different priors: sparsity only, continuity only, and the combined effect of both sparsity and continuity priors.

Fig. 2. Acquisition system and workflow of SC-FROCRT. (a) Automatic 360° acquisition system with the sample arm. (b) Schematic diagram of the SC-FROCRT framework. The reconstruction path is depicted by solid lines.

Fig. 3. Validation of resolution enhancement by SC-FROCRT in a multilayer tape phantom. (a) Reconstruction result comparison for OCT, FROCT, SC-FROCT, and SC-FROCRT. (b) Comparison of global and local magnifications for different methods. Scale bar: 0.5 mm.

Fig. 4. Quantitative reconstruction analysis of the multilayer tape sample. (a) Magnification comparison of different methods, with color-coded boxes for each method. (b) Lateral resolution comparison. (c) FRC correlation metric analysis in the frequency domain. Scale bar: 0.5 mm.

Fig. 5. Ablation study comparison results. (a) Global and locally enlarged region comparisons of the FROCRT, H-FROCRT, and SC-FROCRT techniques. (b) Analysis of the FRC resolution metric. (c) Comparison of lateral and axial reconstruction line profiles. Scale bar: 0.5 mm.

Fig. 6. Comparison of the aloe vera tissue sample reconstruction results. (a) Comparison between the FROCRT and SC-FROCRT methods. (b) Detailed comparison between single-angle imaging methods. (c) Detailed comparison of multi-angle Fourier synthesis reconstruction results. (d) Comparison of SNR for single-angle reconstruction images. (e) Comparison of resolution capability for selected regions. (f) Comparison of the PSF frequency domain spectral range. Scale bar: 0.5 mm.

Fig. 7. Tomographic imaging of the optical-cleared spleen sample. (a) OCT, FROCT, and SC-FROCT images of the spleen. The far-right panel shows magnified views of the regions outlined by dashed boxes. (b) Application of SC-FROCRT to imaging of a spleen sample in a ∼4.0mm×2.5mm area. (c) Magnified views from the white dashed box in (b) under different imaging configurations. (d) Intensity profiles of OCRT, FROCRT, and SC-FROCRT images corresponding to the microtubule filament structures indicated by the white dashed lines in (c). SNR scores for OCRT, FROCRT, and SC-FROCRT, respectively. Scale bar: 0.5 mm.

Fig. 8. Tomographic imaging of the optical-cleared femur sample. (a) Imaging comparison between the FROCT and SC-FROCRT methods. (b) Comparison of single-angle acquisition images. (c) Comparison of multi-angle synthesis reconstruction results. (d), (e) Magnified details of localized regions and lateral intensity curves at gap1 and gap2. (f) Quantitative analysis of resolution through FRC. Scale bar: 0.5 mm.

Fig. 9. 3D high-resolution reconstruction of cleared mouse brain. (a) 3D reconstruction of a part of the mouse brain. (b) 2D tomographic images at different z-axis depths. (c) Photograph of the cleared mouse brain (top view), with the scanned and reconstructed region outlined in the dashed box. Scale bar: 0.5 mm.

Fig. 10. Comparison between different image reconstructions and high-resolution light sheet fluorescence microscopy (LSFM) reconstructions of cleared biological tissues. (a) Image comparison between different image reconstructions. (b) 2D power spectral analysis. (c) Edge resolution analysis.

Fig. 11. Schematic of conjugate artifact removal and Fourier synthesis techniques. (a) Workflow of conjugate artifact removal. The process includes transversal FFT along x, bandpass filtering, and longitudinal FFT along λ, resulting in an extended depth range OCT image without conjugate artifacts. (b) Schematic overview of the multi-angle synthesis workflows for the OCRT, the FROCRT, and the proposed SC-FROCRT techniques.

Fig. 12. Additional data for aloe and spleen tissue images (c.f., Figs. 6 and 7). (a) Aloe sample. (b) Tissue-cleared mouse spleen sample. Scale bar: 1 mm.

Fig. 13. Super-resolution comparison for single-frame plant tissue samples. (a) Different reconstruction results. (b) Magnified details of the reconstructed images. (c) Axial resolution comparison: black line, original OCT; blue line, autocorrelation averaging; red line, SC module. Scale bar: 0.5 mm.