2022 – Winner
A New Holographic Principle – 3D Zero Order Imaging
What was it for and how did it work?
The development of methods for synthesizing flat optical elements to form 3D images began after the work of Denis Gabor, who was awarded the Nobel Prize in physics in 1971 for inventing and developing the holographic recording principle. In particular, Gabor’s follower Stephen Benton developed a method for recording so called rainbow holograms, which form 3D images at the 1st diffraction order when illuminated by a point source of white light. These holograms form a visual 3D parallax in the left-right direction only; when tilted up- down or rotated, the 3D image changes its color and eventually disappears completely.
This year, we proposed a new method for computing and synthesizing nano-optical elements to produce a new visual effect: a 3D image formed in the vicinity of zero diffraction order. The main idea is to set large observation area around zero diffraction order, not at 1st order as it is in tradtional rainbow 3D holograms. Our method for synthesizing nano-optical elements according to the zero-order scheme consists of five steps:
- Render frames using a chosen computer 3D model.
- Split an optical element into elementary regions less than 50 microns in size.
- Determine the angular radiation patterns for each elementary region using the frames rendered.
- Numerically solve the inverse problems of finding the phase function of an optical element in each elementary region according to the angular radiation patterns.
- Record the calculated microrelief of the entire optical element using electron-beam lithography with an accuracy of 10 nm in terms of depth.
The resulting 3D image can be observed well when illuminated by white light, and an observer sees the 3D image with full parallax, both when the optical element is tilted and when it is rotated through 360 degrees (see accompanying videos). In addition, unlike rainbow holograms, the color of the formed 3D image does not depend on the viewing angle – in other words, the formed 3D image behaves like a real 3D object (please see accompanying videos). The method also allows fragments of diffraction gratings to be embedded into the nano-optical element to form an additional 2D image visible at an acute angle.
More technical details about the new holographic principle can be seen in our recent publication in Nature Scientific Reports:
What is significant about this hologram project?
A new holographic principle allows to create 3D images that behave like real 3D objects. An observer sees under white light illumination 3D image with full parallax, both when the optical element is tilted and when it is rotated even through 360 degrees, the color of the formed 3D image does not depend on the viewing angle. At the same time required microrelief forming accuracy is 10nm, which provides the highest level of protection against counterfeiting. Holograms with the new visual effect can be replicated well by using standard equipment for mass production (electroforming, embossing, etc.)