Mid-infrared single-photon 3D imaging

Area of Science:

• Photonics and Imaging Technologies
• Biomedical Optics
• Materials Science

Background:

• Active mid-infrared (MIR) 3D imaging is crucial for biomedical and industrial applications.
• Current limitations include the need for sensitive, fast MIR sensors for low-light imaging.

Purpose of the Study:

• To develop a MIR time-of-flight imaging system with single-photon sensitivity and femtosecond timing resolution.
• To overcome challenges in low-light level MIR 3D imaging.

Main Methods:

• Utilized nonlinear frequency upconversion to optically gate back-scattered MIR photons with ultrashort pump pulses.
• Employed a silicon camera for recording time-stamped, upconverted images.
• Implemented a spatiotemporal correlation-based numerical denoiser for photon-starving conditions.

Main Results:

• Achieved single-photon sensitivity and femtosecond timing resolution in MIR 3D imaging.
• Demonstrated high lateral and depth resolutions for 3D reconstruction.
• Successfully revealed object profiles and reflectivity at detected fluxes below 0.05 photons/pixel/second.

Conclusions:

• The developed MIR 3D imager offers high detection sensitivity and precise timing resolution.
• Its wide-field operation capabilities may advance research in life and material sciences.
• This technology addresses critical challenges in low-light MIR 3D imaging.