Researching pointing error effect on laser linewidth tolerance in space coherent optical communication systems

Area of Science:

• Optical Communications
• Wireless Technologies
• Signal Processing

Background:

• Space coherent optical communication systems require precise alignment.
• Laser phase noise and atmospheric turbulence degrade system performance.
• Pointing errors, including jitter and boresight misalignment, are critical factors.

Purpose of the Study:

• To evaluate the impact of pointing errors on laser linewidth tolerance.
• To develop a bit error rate (BER) model for binary phase-shift-keying (BPSK) modulation.
• To analyze the influence of jitter and boresight variations on linewidth tolerance.

Main Methods:

• Derivation of a closed-form BER model incorporating atmospheric turbulence, pointing error, and laser phase noise.
• Numerical simulations to assess linewidth tolerance based on the BER model.
• Separate and joint analysis of jitter and boresight effects.

Main Results:

• Laser linewidth tolerance decreases significantly with increased pointing error.
• Linewidth tolerance is more sensitive to jitter variations than boresight variations.
• The rate of linewidth tolerance decrease accelerates with larger pointing errors.

Conclusions:

• Pointing error is a critical design parameter for space coherent optical communication systems.
• System design must account for jitter and boresight effects to maintain laser linewidth tolerance.
• The developed BER model provides a valuable reference for system optimization.