A tunable Shack–Hartmann wavefront sensor based on a liquid-filled microlens array

A novel design concept for a Shack–Hartmann sensor is presented. A liquid-filled microlens array is used to replace the commonly used microlens array with fixed focal length in a conventional type. The focal length tunabilty associated with this design can provide the device with the advantage that its performance can be flexibly chosen between a large dynamic range and a high sensitivity preferred region. At the same time, it is also possible to possess both of these characteristics simultaneously with a particular procedure. This feature allows the device to be operated in different applications. The results of a prototype demonstrated in this paper qualitatively verify this feasibility, and the potential application perspective of this design is also presented.