In a first, scientists have developed an
invisibility cloaking technique based on the
manipulation of the frequency of light
waves as they pass through an object,
breakthrough that could make 3D objects
invisible from all directions.
The new device, developed by researchers
from the US-based 'The Optical Society,
scientific society dedicated to advancing
the study of light, is known as spectral
invisibility cloak. The device can
completely hide arbitrary objects under
broadband illumination (with light sources
containing many colours), unlike the
cloaking devices currently in use, which
can conceal the object of interest only
when the object is illuminated with just one
colour of light, researchers said.
Experimental atom light process
could be constructive for sensing,
telecommunications and information
processing technologies. It could be further
extended to make 3D objects invisible
from all the directions. "Our work
represents a breakthrough in the quest for
invisibility cloaking," said Jose Azana, one
of the researchers in the team.
"We have made a target object fully
invisible to observation under realistic
broadband illumination by propagating the
illumination wave through the object with
no detectable distortion, exactly as if the
object and cloak were not present," Azana
said.
Scene from Harry-Potter
development before it could be translated
into a Harry Potter-style wearable
invisibility cloak, the demonstrated spectral
cloaking device could be useful for a range
of security goals.
"Conventional cloaking solutions rely on
altering the propagation path of the
illumination around the object to be
concealed; this way, different colours take
different amounts of time to traverse the
cloak, resulting in easily detectable
distortion that gives away the presence of
the cloak," said another researcher Luis
Romero Cortes.
"Our proposed solution avoids this problem
by allowing the wave to propagate through
the target object, rather than around it,
while still avoiding any interaction between
the wave and the object," he added. The
team is also working to advance practical
applications for single-direction spectral
cloaking in one-dimensional wave systems,
such as for fibre optics-based applications.
