High-capacity imaging and rotationally insensitive object identification with correlated orbital angular momentum states

Using no conventional measurements in position space, information extraction rates exceeding one bit per photon are achieved by employing high-dimensional correlated orbital angular momentum (OAM) states for object recognition. The correlations are shown to be insensitive to axial rotation of the target object: The information structure of an object's joint OAM coincidence spectrum is unchanged even when the object undergoes random rotations between each measurement. Additionally, OAM correlations alone are shown to be sufficient for full image reconstruction of complex, off-axis objects, and novel object symmetries are observed in the phases of OAM-object interaction transition amplitudes. Variations in mutual information rates, due to off-axis translation in the beam field, are studied, and it is shown that object symmetry signatures and information rates are independent of environmental factors sufficiently far from the beam center. The results motivate dynamic scanning applications in contexts where symmetry and small numbers of noninvasive measurements are desired.