If you still thinking becoming invisible is not possible and only looks good in movies like Harry Potter then think twice because the scientists are one step closer to wearing the invisible cloak in real life! Yes, you heard right, the scientists have developed a new technology that allows objects to be invisible in the sun.
It is spectral camouflage technology that makes an object invisible by changing the frequency of light that interacts with the object.
Scientists have not invented an invisibility cloak like the one used in Harry Potter yet, but this new technology will be the foundation and help for developing the hidden artifacts of the future!
How do people see the color?
The electromagnetic spectrum consists of a large number of frequencies, including radiation that is invisible to the naked eye, such as x-rays and microwaves.
The range of frequencies that humans can detect in the spectrum is visible light, which itself contains different frequencies, ranging from red at one end to purple at the other end.
Some light sources, such as the sun, have multiple frequencies, which are called broadband sources. When a person sees an object, what he actually sees is the interaction between light and the object.
For example, when a person sees a red apple, what he actually sees is the red frequency of an apple reflecting the sun. All other colors are penetrating, so this is why people can’t see other colors except red.
Researchers at the National Institute of Science in Montreal, Canada have developed a spectral stealth technique that utilizes a variety of visible frequencies. This new technology aims to address the limitations of early stealth technology.
Early techniques usually influenced the interaction between light and objects by manipulating the light waves around the object, rather than letting the light waves pass directly through the object.
Light of different colors surrounds objects in different paths and reaches their destination at different times. The result is a degree of distortion, so in the early experiments, the object was not actually completely invisible.
Other techniques do not produce the same distortion, although they are only invisible in the light of one color in the laboratory. But obviously, this is almost impossible to put into practical use in our world where the lighting is wide.
Spectral camouflage technology
In a new study published in Optica magazine, researchers led by telecom engineer Jose Azana have developed a new device that can make objects invisible by controlling the frequency of light as it passes through an object.
When light passes through an object, the device works by converting light of one frequency to another. Once it passes, the frequency will return to its original state.
By using this method, light passes through the object but does not interact with it, making the observer invisible.
If you have a green mango, the spectral stealth it by shifting the green light frequency to another frequency as the light passes through the mango. Once the light passes through the mango, the green light frequency is moved back to its original position, making the green mango invisible.
The device has two components that work by forcing the light frequencies to move at different speeds and then changing the specific frequency as the light passes through the object. One is placed in front of the object and the other is placed behind.
The researchers used the device to make the optical filter invisible when illuminated by a beam of light. Optical filters reflect light in certain colors while passing other colors, creating an optical filter that is invisible under laser illumination.
Jose Azana said: “By passing the illumination wave through the object without causing detectable distortion, we have made a target completely invisible under realistic broadband illumination, just as objects and cloaks do not exist.”
Spectral camouflage application
The device is still in its infancy and has not yet resolved its limitations. Currently, spectral camouflage can only be done in one direction. The observer must stand on the path of light so that the object is invisible to him.
The researchers said that the device could be coded in the future to modify all frequencies in the entire visible spectrum. This will make an object invisible no matter what direction, and this is what the researchers hope to achieve one day.
They are also looking for ways to apply in the real world to get invisible and directional research. Researchers say spectral camouflage technology can be used for security purposes in the military and telecommunications industries.
By using this technology to make the cable invisible, the company can prevent commercial espionage from peeping through the telecommunications line as confidential information for broadband signal transmission.