Proof of Concept FENG/ FnP

Project title: Retinal display based on two-photon vision for augmented reality

One of the main problems with augmented reality (AR: Augmented Reality) technologies is that simultaneously achieving satisfactory clarity and quality: (1) the image of the outside world and (2) the additional information displayed against it, requires a compromise. Current solutions on the market are mainly based on fibre-optic technology. Spectacle lenses are specially designed flat optical waveguides that transport light carrying information into the eye, with light coming from outside passing through. However, both diffractive waveguides (e.g. Hololens) and reflective waveguides (e.g. Lumus Z-lens) affect the course of light from the surroundings, ultimately resulting in a dim and to some extent distorted image of the outside world. These problems are exacerbated when the waveguide structure has to take into account the different colours of the display. This project aims to verify the implementation potential of a retinal display concept using two-photon vision. This is a recently discovered vision mechanism that extends the range of perceived radiation into the near infrared (850-1300 nm). Two-photon vision is based on a non-linear optical process – two-photon absorption occurring in visual pigments. The laser beams that we see two-photonally have a colour close to half their wavelength: for 950 nm – blue, for 1000 nm – green and for 1200 nm – red. Due to the differences in wavelengths of ambient light and the AR stimulus, two-photon vision could be facilitated by combining the two optical pathways in glasses. The non-linear nature of the phenomenon means that it occurs efficiently only at the focus of the beam focused on the retina, so duplicate reflections as well as scattered light are not perceived, and two-photon stimuli have better contrast. These hypotheses will be verified by building a prototype AR glasses with two-photon vision and psychophysical tests conducted with it.

The total funding for this project is PLN 698 880.