High-precision DSM-based laser ranging method integrated with free space optical communication

Area of Science:

• Optical Engineering
• Communication Systems
• Sensing Technology

Background:

• Free space optical communication (FSOC) is rapidly advancing with diverse applications including satellite, UAV, and underwater systems.
• High-precision position and distance information are crucial in many FSOC applications, often requiring dedicated laser ranging technology.
• Existing integrated FSOC and laser ranging solutions face limitations in ranging accuracy, typically at the millimeter level.

Purpose of the Study:

• To enhance the accuracy of laser ranging and improve the communication rate within an integrated FSOC architecture.
• To develop a novel method for combining laser ranging with high-speed FSOC to reduce terminal size, weight, and power.
• To demonstrate a new approach for achieving sub-millimeter ranging precision in integrated optical communication systems.

Main Methods:

• Proposed a harmonic phase ranging method integrated with delta-sigma modulation (DSM).
• Implemented the method on a 10 Gb/s coherent FSOC system.
• Utilized DSM to convert harmonic signals into digital data for combined transmission with communication data.

Main Results:

• Achieved a root mean square error (RMSE) of approximately 0.303 mm for laser ranging.
• Successfully integrated laser ranging capabilities into a high-speed FSOC link.
• Demonstrated improved ranging precision compared to existing millimeter-level solutions.

Conclusions:

• The proposed harmonic phase ranging method combined with DSM offers superior laser ranging accuracy.
• The integrated architecture effectively combines high-precision ranging with high-speed FSOC.
• This approach presents significant advantages for applications requiring both accurate distance measurement and high data rates in optical communication.