In the picture, you can see ITMO Univeristy’s logo projected by the augmented reality system.
The augmented reality system includes a microprojector that forms the image and a special waveguide made out of photo-thermo-refractive glass (PTR). The waveguide ensures the image transmission from the microprojector to the user’s eye.
The image remains sealed in the waveguide during this process. Holographic Bragg gratings are used in order to insert it from the microprojector into the waveguide – these gratings allow us to avoid total internal reflection and seal the light from the microprojector inside the waveguide.
Once the light reaches the user’s eye, a similar set of holograms extracts the light from the waveguide and the image forms in front of the eye.
Images projected in this way can be seen clearly both from short and long distances. There is no quality loss at the waveguide with the used wavelength and that’s what provides the image with high brightness and contrast levels. The system was created by ITMO University’s Research Center for Optical Material Engineering and the Research Institute of Radioelectronics and Laser Technology (Bauman Moscow State Technical University).