Double drive modes unimorph deformable mirror for low-cost adaptive optics

Area of Science:

• Optics and Photonics
• Adaptive Optics
• MEMS Technology

Background:

• Deformable mirrors (DMs) are crucial components in adaptive optics systems for correcting wavefront aberrations.
• Existing DMs can be costly and complex, necessitating the development of more accessible solutions.

Purpose of the Study:

• To develop and characterize a low-cost, thin unimorph deformable mirror (DM) driven by positive voltage.
• To investigate the DM's performance for aberration correction and defocus bias generation.

Main Methods:

• Fabrication of a thin unimorph DM with an inner actuator array for aberration correction and an outer ring actuator for defocus bias.
• Utilizing an analytical model based on plate and shell theory to predict DM behavior.
• Experimental characterization of deformation capabilities, resonant frequency, and surface accuracy.

Main Results:

• The DM demonstrated maximum defocus deformations of -14.3 μm and 14.9 μm.
• A resonant frequency of 1.8 kHz was measured.
• The root-mean-square deformation after correction was better than λ/20 for λ=633 nm.
• Accurate replication of Zernike modes up to the fifth order was achieved.

Conclusions:

• The developed low-cost deformable mirror is suitable for low-order aberration correction.
• The dual-actuator design allows for both precise aberration correction and overall defocus adjustment.
• This technology offers a cost-effective solution for adaptive optics applications.