A new way of creating compact holograms have been developed by scientists. These holograms that work across the spectrum of light, not only prevents fraud but also provides better entertaining displays. Though this holographic technology is available for decades, even today researchers are struggling to make compact holograms which are more efficient, complex and secure. In US researchers of Harvard University have programmed polarisation into compact holograms, which use nano structures which are sensitive to the direction in which light vibrates, to create images depending on the direction of incident light. The new improved holograms which works across the spectrum of light, not only improves anti-fraud holograms but also entertainment displays.
A Professor at Harvard, Mr. Federico Capasso said The novelty in this research is that by using nanotechnology, we’ve made holograms that are highly efficient, meaning that very little light is lost to create the image. Capasso said by using incident polarised light, you can see a far crisper image and can store and retrieve more images. He added that Polarisation adds another dimension to holograms that can be used to protect against counterfeiting and in applications like displays.
Digital photographs like Holograms, are known to capture a field of light around an object and there by get it encoded on a chip. Holograms appear three-dimensional as they capture the phase of light on the other hand photographs only record the intensity of light. A postdoctoral fellow of Capasso Lab Mohammadreza Khorasaninejad said our holograms work like any other but the image produced depends on the polarisation state of the illuminating light, providing an extra degree of freedom in design for versatile applications. There are many states of polarisation. The direction of vibration remains constant in linearly polarization but we find it rotates clockwise or counterclockwise in circularly polarization.
