  We demonstrate the rotational memory effect in a multimode fiber. Rotating
the incident wavefront around the fiber core axis leads to a rotation of the
resulting pattern of the fiber output without significant changes in the
resulting speckle pattern. The rotational memory effect can be exploited for
non-invasive imaging or ultrafast high-resolution scanning through a multimode
fiber. Our experiments demonstrate this effect over a full range of angles in
two experimental configurations.
