Wavelength-multiplexed multiplane quantitative phase imaging using a diffractive optical processor

We present deep learning-designed all-optical processors that can perform multiplane quantitative phase imaging (QPI). By leveraging diffractive processing and wavelength multiplexing, our approach allows the direct capture of quantitative phase distributions of input objects located at different axial planes using an intensity-only image sensor, eliminating the need for digital phase recovery algorithms. A proof-of-concept experiment validated the approach, showcasing successful imaging of distinct phase objects at different axial positions in the terahertz spectrum. By providing a faster, more efficient method for QPI, this technology can be applied to medical diagnosis, material science, and environmental monitoring, among other applications.