Quantitative phase gradient microscopy with spatially entangled photons

Area of Science:

• Quantum Optics
• Microscopy
• Image Reconstruction

Background:

• Conventional phase imaging methods often require interferometry, scanning, or complex algorithms.
• These limitations restrict their application, especially for dynamic or photosensitive samples.

Purpose of the Study:

• To develop an entanglement-based quantitative phase gradient microscopy technique.
• To enable simultaneous, non-local measurement of sample transmission and phase gradient.
• To achieve high-resolution amplitude and phase recovery without traditional limitations.

Main Methods:

• Utilizes position-momentum entangled photon pairs for illumination.
• One photon interacts with the sample (near-field), the other provides reference (far-field).
• Leverages quantum correlations for dual-domain measurement and image reconstruction.

Main Results:

• Achieved quantitative phase and amplitude imaging with 2.76 μm spatial resolution.
• Demonstrated phase sensitivity of λ/100 with femtowatts of illuminating power.
• Showcased robustness against dynamic and structured background light.

Conclusions:

• The developed technique circumvents limitations of conventional phase imaging.
• Offers a powerful tool for non-invasive imaging of photosensitive samples.
• Has potential applications in adaptive optics and imaging under challenging lighting conditions.