Wavelength-time coding for multispectral 3D imaging using single-photon LiDAR.

Area of Science:

• Photonics
• Computational Imaging
• Optical Engineering

Background:

• Single-photon light detection and ranging (LiDAR) enables color reconstruction and target identification in low-light conditions.
• Existing multispectral LiDAR systems often require complex receiver channels with wavelength routers.

Purpose of the Study:

• To present a novel 3D imaging system using time-of-flight LiDAR for simultaneous multispectral measurements with a single photon detector.
• To develop a computational method for reconstructing spectral and depth profiles from single-pixel waveforms in photon-starved environments.

Main Methods:

• A time-of-flight LiDAR system utilizing a single-photon detector for simultaneous multispectral measurements (four visible wavelengths).
• Leveraging chromatic group delay dispersion in optical fiber to create wavelength-to-time mapped peaks within a single waveform.
• Development of a multispectral single waveform algorithm to analyze multi-peaked waveforms and reconstruct spectral and depth information.

Main Results:

• The system successfully obtains a single waveform with time-mapped peaks corresponding to different wavelengths.
• The proposed algorithm accurately fits these waveforms, enabling the reconstruction of color (spectral response) and depth profiles.
• Demonstration of the first computational method in the photon-starved regime capable of discriminating multiple wavelength peaks within a single pixel waveform.

Conclusions:

• The presented system and algorithm offer a simplified yet effective approach to multispectral LiDAR imaging without a receiver wavelength router.
• This method advances photon-starved imaging by enabling simultaneous spectral and depth reconstruction from single-pixel waveforms.
• The work represents a significant step towards enhanced target identification and color reconstruction in challenging imaging scenarios.