Abstract
Three-dimensional (3D) displays allow users to experience 2D images/videos
in-depth illusions. Among the different 3D displays, we can distinguish the
Pepper ghost illusion, which is a common approach to create a 3D hologram
without goggles. In this work, we have upgraded the conventional Pepper
ghost illusion, named as the two-way Pepper ghost tunnel, to create two
simultaneous holograms. Contrary to the conventional Pepper ghost, the
Pepper ghost tunnel requires two liquid crystal displays (LCDs), which
are controlled by the same Arduino, to illuminate a 45-deg transparency
sheet in both directions, allowing two different holograms to be viewed
from each side of the tunnel. We have described a practical procedure for
building the apparatus and validate its performance. Due to the simplicity
of the apparatus, the Pepper Ghost tunnel allows undergraduate students
to increase their knowledge in geometrical Optics and its integration with
electrical circuits.