  In this paper, we present the proof of concept of a very fast adaptive glass
membrane lens with a large aperture/diameter ratio, spherical aberration
correction and integrated actuation. The membrane is directly deformed using
two piezo actuators that can tune the focal length and the conical parameter.
This operating principle allows for a usable aperture of the whole membrane
diameter. Together with the efficient actuation mechanism, the aperture is
around 2/3 of the total system diameter - at a thickness of less than 2mm. The
response time is a few milliseconds at 12mm aperture, which is fast compared to
similar systems.
