Multi-pass microscopy

Area of Science:

• Quantum optics
• Microscopy
• Image processing

Background:

• Low-light microscopy is crucial for delicate biological specimens but suffers from shot noise.
• Achieving the Heisenberg limit for measurement accuracy is a key goal in high-resolution imaging.
• Quantum correlations offer a path to improve accuracy beyond classical limits.

Purpose of the Study:

• To develop a microscopy technique that achieves Heisenberg-limited accuracy by overcoming shot noise.
• To enhance measurement precision in low-light conditions, especially when sample damage is a concern.
• To demonstrate the applicability of the technique for imaging and diffraction studies.

Main Methods:

• Utilized self-imaging cavities and temporal post-selection for multi-pass imaging.
• Implemented sequential photon passes through the specimen to enhance signal.
• Performed full-field multi-pass polarization and transmission microscopy.

Main Results:

• Achieved variance reductions of 4.4±0.8 dB (polarization) and 4.8±0.8 dB (transmission) compared to the single-pass shot-noise limit.
• Demonstrated a variance reduction of 25.9±0.9 dB when accuracy is limited by detected particles.
• Showcased contrast enhancement in imaging nanostructured samples and kidney cells.

Conclusions:

• The developed multi-pass microscopy approach enables Heisenberg-limited imaging without requiring quantum state engineering.
• This technique significantly reduces noise and enhances contrast, improving the quality of low-light microscopy images.
• The method is versatile and applicable to various imaging and diffraction studies of delicate samples.