All-fiber coherent laser image Lidar based on phase correction.

Area of Science:

• Optics and Photonics
• Remote Sensing Technologies
• Signal Processing

Background:

• All-fiber coherent lidar systems struggle with weak signal detection due to local oscillator power instability.
• Extracting target intensity images is challenging when echo signals are weaker than noise.
• Existing methods may require complex optical setups, limiting practical application.

Purpose of the Study:

• To develop an advanced intensity imaging method for all-fiber coherent lidar systems.
• To enhance the detection sensitivity for weak target echo signals.
• To simplify the coherent lidar system by minimizing the need for extra optical components.

Main Methods:

• Implemented a phase compensation technique to correct heterodyne signal positioning in the time domain.
• Developed a novel algorithm to extract weak echo signals from corrected heterodyne signals.
• Analyzed system performance using metrics like false alarm rates, range accuracy, intensity accuracy, and speckle characteristics.

Main Results:

• Successfully corrected for noise impact on positioning heterodyne signals.
• Obtained relative echo signal intensity for single pixel points.
• Validated the imaging method's effectiveness through comprehensive analysis.

Conclusions:

• The proposed numerical phase correction method significantly improves weak signal extraction in all-fiber coherent lidar.
• The technique enhances target detection sensitivity and simplifies system design.
• This advancement is crucial for improving remote imaging capabilities in coherent lidar systems.