Official demo for Geometry-Aware Phase Compensation (GPC) and Local Phase Correction (LPC) techniques designed for sampling-efficient Angular Spectrum Method (ASM) propagation in thick optical systems.
This repository demonstrates a computationally efficient methodology for simulating light propagation through thick refractive elements (e.g., lenslets, micro-optics) at high incident angles.
Traditional single-step ASM often suffers from numerical instability and phase errors when dealing with geometric thickness. Our approach introduces:
- Global Phase Correction (GPC): Accounting for the bulk phase evolution through the material.
- Local Phase Correction (LPC): An advanced coordinate-skewing technique that preserves the optical path accuracy by accounting for local ray-slanting within the material.
- Multi-Slice ASM (MS-AS): A high-fidelity benchmark that slices the optical element into thin layers to minimize propagation error.
- Single-Slice ASM (SS-AS): An ultra-efficient model utilizing GPC and LPC to achieve benchmark-level fidelity in a single axial step.
- 2x5 PSF Matrix: Automated visualization comparing 5 simulation variants across both Front (curved first) and Back (flat first) lens orientations.
- Quantitative Metrics: Integrated MS-SSIM and Centroid (µm) calculation for quantitative fidelity verification.
The simulation is built using PyTorch for GPU acceleration and automatic differentiation compatibility.
- Python: 3.8+
- CUDA: Recommended for larger grid sizes (e.g., 1500x1500px).
To run the full PSF fidelity study and generate the result visualizations:
python optical_demo_main.pyYou can adjust the following parameters in optical_demo_main.py:
PxSize: Spatial sampling resolution (default: 1.0µm).Grid_Window: Spatial domain size (default: 1.5mm).WD: Distance from the lens to the sensor (Working Distance).Lens_Dia: Lens Diameter (default: 1.0 * mm)ROC: Radius of curvature of the lens (default: 2.0mm).lens_thick: Thickness of the lens (default: 100µm).n_mat: Refractive index of the lens (default: 1.54).n_bkgd: Refractive index of the background (default: 1.0).Illum_Dia: Diameter of the illumination aperture (default: 0.7mm).wavelength: Wavelength of the light (default: 550nm).angle_deg_x: Incident wave angle in degrees (default: 20).angle_deg_y: Incident wave angle in degrees (default: 0).dz_gt: Ground truth propagation distance (default: 1.0µm).dz_coarse: Coarse propagation distance (default: 50.0µm).Crop_window: Region of interest for analysis.
optical_demo_main.py: Main orchestration script for simulation, metric calculation, and visualization.optical_demo_utils.py: Core physics engine containing MS-AS, SS-AS, and GPC/LPC implementations.
Imaging Intelligence Lab, SNU | 2026. 02. 24