Fabrication and evaluation of Dihedral Corner Reflector Array for floating image manufactured by synchrotron radiation

We propose a new imaging optics called Dihedral Corner Reflector Array (DCRA) which is designed to make the floating image. DCRA consists of numerous micro-mirrors placed perpendicular to the surface of substrate. The micro-mirror array is implemented by the inner walls of minute square holes or the side of minute square pillar. We can choose two types of the structure. The primordial is based on two reflections by a pair of adjacent mutually perpendicular mirrors, i.e., a dihedral corner reflector. Although the principal of operation is based on reflection by mirrors, the device is also transmissive and deflects light. Primordial of DCRA is not so complicated, However, it is too difficult to fabricate the DCRA by usual machining because of high aspect ratio micromachining and high mirror accuracy. Therefore, in this manuscript, we fabricated the device by deep X-ray lithography due to synchrotron radiation. The characteristics of the fabricated DCRA are evaluated by the optical transmission and reflection measurements.