Photography determines the amount of light of various colors that hit the photographic film. Since light has dual properties of a particle and a wave, it can be characterized by the phase because of its wavelike properties. Phase is a particular point in time on the cycle of a waveform, measured as an angle in degrees. Optical holography is a method of storage and displaying a three-dimensional image of an object.
The wavelength of light is a concern for the spatial resolution of the photo/hologram when it is near 1 μm (0.001 mm). This will be a problem if it enters nanotechnology.
EPFL researchers have developed a method to observe the behavior of light even beyond its limitation on wavelength. These scientists utilized freely propagating electrons as their photography media. This method allows providing quantum information in a holograph trapped in a nanostructure through an ultrafast electron microscope.
"The scientists used the quantum nature of the electron-light interaction to separate the electron-reference and electron-imaging beams in energy instead of space. This makes it now possible to use light pulses to encrypt information on the electron wave function, which can be mapped with ultra-fast transmission electron microscopy," according to IT Tech Post.
Two benefits can be obtained from this new method. Properties of light and how it can be used as a tool in imaging electromagnetic fields with attosecond and nanometer precision in time and space can be determined. Another is that it can be utilized in quantum computing applications to control the quantum properties of free electrons.
"Conventional holography can extract 3D information by measuring the difference in distance that light travels from different parts of the object," says Carbone. "But this needs an additional reference beam from a different direction to measure the interference between the two. The concept is the same with electrons, but we can now get higher spatial resolution due to their much shorter wavelength. For example, we were able to record holographic movies of quickly moving objects by using ultrashort electron pulses to form the holograms."
"So far, science and technology have been limited to freely propagating photons, used in macroscopic optical devices," says Carbone. "Our new technique allows us to see what happens with light at the nanoscale, the first step for miniaturization and integration of light devices onto integrated circuits."
