Precise adjustment of the three-dimensional position of the deformable mirror in adaptive optics-assisted microscopy

Adaptive optics (AO) assisted microscopy enables high-quality imaging by correcting instrument- and specimen-induced aberrations, utilizing wavefront shaping devices such as a deformable mirror (DM). For optimal wavefront modulation, it is crucial to position the DM accurately at the conjugate pupil plane and align it symmetrically with the optical axis. However, achieving these requirements can be challenging for researchers lacking a background in AO instrumentation. Here, we propose a simple and practical approach for precisely adjusting the three-dimensional position of the DM using a custom-made bead sample. The experimental results demonstrate the effectiveness of this approach, achieving uniform phase modulation across a total field of view of 60 μm × 60 μm, with a standard deviation of <0.1 λ/2π in the decomposed Zernike coefficients from Z5 to Z25 in Wyant order.