Optomechanics of a stable diffractive axicon light sail

Area of Science:

• Optomechanics
• Applied Physics
• Space Propulsion

Background:

• Beamed propulsion using light sails offers a promising method for spacecraft acceleration.
• Traditional light sails face challenges with stability, particularly walk-off and tumbling, during propulsion.
• Passive self-stabilization mechanisms are crucial for reliable light sail operation.

Purpose of the Study:

• To investigate the optomechanics of a novel light sail design for enhanced stability.
• To mitigate catastrophic sail walk-off and tumbling using a diffractive film.
• To analyze the trade-off between stability and longitudinal acceleration in beamed propulsion.

Main Methods:

• Modeling a rigid, non-spinning light sail equipped with a flat axicon diffraction grating.
• Performing linear stability analysis of the sail's motion.
• Conducting numerical integration of coupled translational and rotational equations of motion.

Main Results:

• The proposed diffractive film provides passive self-stabilization, enabling "beam riding."
• The system achieves 90% of the theoretical longitudinal force limit for beamed propulsion.
• Stability is maintained against relative sail translation up to 30% of the sail radius.

Conclusions:

• A flat axicon diffraction grating effectively stabilizes light sails against walk-off and tumbling.
• The design offers a viable solution for stable and efficient beamed propulsion.
• This approach balances high longitudinal acceleration with robust operational stability for space missions.