Refractive adaptive optics microscopy with an optofluidic phase modulator

The past decade has seen the emergence of several novel refractive wavefront modulator technologies based on either piezoelectric or electrostatic actuators, which are functionally equivalent to deformable mirrors but work in transmission. Therefore, they can be potentially integrated into advanced imaging instruments without relay optics, and/or with significantly alleviated alignment and stability issues. This opens new avenues for wider deployment of AO in life-science microscopy. The Deformable Phase Plate (DPP) developed in our group is one such technology, distinguished by its exceptionally compact dimensions, capability of high-order correction, and scalability, which render it particularly useful for upgrading existing instruments with AO capability. Recently, we have integrated the DPP into both commercial and research-grade microscopes, employing various sensorless wavefront estimation techniques to minimise hardware modifications. This paper summarises the experimental results and provides a critical evaluation of the feasibility and limitations of plug-and-play AO upgrades from an end-user perspective.