Concept, modeling, and performance prediction of a low-cost, large deformable mirror

Area of Science:

• Astronomy and Astrophysics
• Optical Engineering
• Control Systems

Background:

• Integrating deformable mirrors (DM) directly into telescopes for adaptive optics (AO) is desirable but costly for large apertures.
• Existing low-cost DM designs using voice-coil actuators suffer from poor damping and numerous structural modes.
• Effective control of mirror dynamics is crucial for integrating these DMs into AO systems.

Purpose of the Study:

• To introduce a cost-effective distributed control approach for large deformable mirrors in adaptive optics.
• To demonstrate the feasibility of a low-cost DM strategy within a closed-loop AO system.

Main Methods:

• Developed a distributed control approach for voice-coil actuated deformable mirrors.
• Utilized electro-mechanical sensors and realistic models of low-cost actuators and sensors.
• Incorporated an atmospheric seeing model to simulate performance.

Main Results:

• Showcased that the "inner" back sensor control loop does not require low-frequency operation, enabling significant sensor cost reduction.
• Demonstrated the feasibility of the low-cost mirror strategy within a closed-loop AO system.
• Validated the approach using realistic models and an atmospheric seeing model.

Conclusions:

• A distributed control strategy allows for the use of inexpensive voice-coil actuators in large deformable mirrors for adaptive optics.
• Reduced sensor requirements in the control loop lead to substantial cost savings.
• This low-cost deformable mirror approach is viable for adaptive optics systems in large telescopes.