  We present a new kind of varifocal mirror with independently adjustable
curvatures in the major directions. For actuation we use two stacked piezo
bending actuators with crossed in-plane polarization. This mirror can be used
for example as an off-axis focusing device with tunable focal length and
compensation for a variable angle of incidence or for coma correction. We
demonstrate the prototype of such a mirror and characterize the mechanical
deflection, as well as the focusing capabilities.
