Sideband suppression method for fiber optic phased array coherent LiDAR echo signal based on periodic matching

Area of Science:

• Optics
• Photonics
• Signal Processing

Background:

• Sideband effects in fiber optic phased array coherent LiDAR degrade target frequency detection accuracy.
• Accurate frequency detection is crucial for LiDAR applications, especially for micro-motion targets.

Purpose of the Study:

• To propose and validate a novel sideband suppression method for fiber optic phased array coherent LiDAR.
• To enhance the frequency detection accuracy of target detection systems.

Main Methods:

• Establishment of a theoretical model for sideband amplitude using periodic matching.
• Simulation of periodic matching modes to study their impact on time-frequency distribution and echo signal sideband amplitude.
• Experimental validation of the proposed method on ellipsoidal micro-motion targets.

Main Results:

• Decreased maximum sideband amplitude with reduced scanning duration percentage within the combined period.
• Negative correlation found between the percentage threshold and the signal-to-noise ratio of the echo signal.
• Experimental results show an approximate 5-fold increase in frequency measurement accuracy for micro-motion targets.

Conclusions:

• The proposed periodic matching method effectively suppresses sidebands in fiber optic phased array coherent LiDAR.
• The technique improves frequency measurement accuracy without requiring additional optical components.
• This method provides a foundational advancement for the practical application of fiber optic phased array LiDAR.