PS$^{2}$2 F: Polarized Spiral Point Spread Function for Single-Shot 3D Sensing.

Area of Science:

• Optics and Photonics
• Computer Vision
• Microscopy

Background:

• Traditional microscopic imaging struggles with complex scenes.
• Existing point spread functions (PSFs) like DHPSF are limited to sparse light sources.
• Depth estimation accuracy is crucial for 3D reconstruction and analysis.

Purpose of the Study:

• To develop a compact snapshot monocular depth estimation technique.
• To improve depth accuracy in complex microscopic scenes.
• To overcome limitations of existing PSF designs.

Main Methods:

• Engineered a novel point spread function (PSF) based on Double-Helix PSF (DHPSF) properties.
• Utilized a compact polarization-based optical setup with orthogonal polarizers.
• Employed a polarization-sensitive camera to capture separated images.
• Analyzed performance using Cramér-Rao lower bound for theoretical validation.

Main Results:

• Achieved up to 50% lower depth error compared to DHPSF and Tetrapod PSF.
• Demonstrated high depth accuracy even in complex scenes.
• Maintained spatial resolution with minimal loss.
• Validated through simulations and a functional lab prototype.

Conclusions:

• The proposed technique offers superior depth estimation accuracy for complex scenes.
• Compact polarization-based optical design enables efficient snapshot monocular depth estimation.
• This method advances capabilities in microscopic imaging and 3D reconstruction.