Frequency-modulated continuous-wave 3D imaging with high photon efficiency.

Area of Science:

• Photonics
• Optical Engineering
• Imaging Science

Background:

• Frequency-modulated continuous-wave (FMCW) Light Detection and Ranging (LIDAR) is crucial for active 3D imaging due to its high resolution and environmental robustness.
• Traditional FMCW LIDAR requires hundreds of photons per pixel for accurate 3D imaging, limiting its effectiveness in low-flux regimes where depth estimation is unreliable.

Purpose of the Study:

• To develop and demonstrate a photon-efficient FMCW LIDAR approach.
• To improve the robustness and quality of 3D depth estimation in low-photon count scenarios.

Main Methods:

• Constructed an FMCW LIDAR setup utilizing single-photon detectors and a weak local oscillator for coherent detection.
• Implemented a novel imaging approach that leverages data from neighboring pixels to enhance depth estimates.
• Employed a total-variation seminorm technique to effectively reduce noise in the recovered depth maps.

Main Results:

• Achieved high-quality 3D imaging using approximately 10 signal photons per pixel, a tenfold increase in photon efficiency compared to traditional methods.
• Demonstrated the effectiveness of the proposed method through both simulations and experimental validation.
• Confirmed the approach's ability to produce robust depth estimates even at very low photon counts.

Conclusions:

• The developed photon-efficient FMCW LIDAR approach significantly enhances imaging capabilities in low-light conditions.
• This advancement is highly valuable for developing low-power and high-speed FMCW LIDAR applications.
• The method offers a practical solution for improving 3D imaging performance where photon counts are limited.