Distortion correction strategy in off-axis metasurface holography

Area of Science:

• Optics and Photonics
• Image Processing
• Nanotechnology

Background:

• Metasurface holography enables miniaturized optical systems but suffers from image distortions due to off-axis effects and discretization errors.
• These distortions limit the development and performance of off-axis metasurface holography.

Purpose of the Study:

• To implement and evaluate a distortion correction method for metasurface holography using image processing.
• To analyze the impact of a distortion magnitude parameter (DMP) on imaging quality and identify optimal correction ranges.

Main Methods:

• Applied inverse distortion to target images via image processing, converting Cartesian coordinates to polar coordinates.
• Utilized a cubic distortion term with a distortion magnitude parameter (DMP) for coordinate processing.
• Mapped modified polar coordinates back to Cartesian coordinates and quantitatively analyzed imaging performance using SSIM, PSNR, and intensity correlation coefficient.

Main Results:

• Increasing the DMP from 0 to 3.2 progressively reduced distortion and enhanced imaging quality.
• Achieved maximum improvements of 0.0864 in SSIM, 1.83 dB in PSNR, and 0.0979 in intensity correlation coefficient.
• Identified an optimal DMP range for effective correction, noting that excessive modulation leads to negative distortion.

Conclusions:

• The proposed image processing method effectively corrects distortions in metasurface holography, enhancing imaging quality.
• Experimental verification confirmed the simulation results, supporting the expansion of metasurface holographic imaging capabilities.
• This work significantly advances the performance and applicability of off-axis metasurface holography.