Adaptive carrier-aligned local spectral sampling for fast and accurate phase retrieval in off-axis digital holography

Off-axis digital holography enables single-shot quantitative phase imaging yet typically requires balancing computational efficiency against reconstruction accuracy. To alleviate this limitation, an adaptive carrier-aligned local spectral sampling method is proposed for fast and accurate phase retrieval. The spatial carrier is estimated with sub-pixel precision via a Fourier‑domain simplex carrier optimization, and a carrier-centered local sampling grid is constructed to extract only the effective spectral band of the cross-correlation term. Back-projection reconstruction is then applied to recover the full-resolution phase. This method avoids full-spectrum Fourier transform computation and spectrum shifting while suppressing spectral leakage caused by frequency-grid mismatch. Simulations and experiments show that the proposed method achieves higher reconstruction accuracy for both smooth and step phases while offering improved computational efficiency over existing methods.