Polish scientists have developed what they describe as the world’s first prototype of augmented-reality glasses based on two-photon vision. Instead of relying only on visible light, the system uses short pulses of near-infrared radiation to create images perceived by the human eye as visible colours.
The technology is being developed by researchers including Prof. Katarzyna Komar of Nicolaus Copernicus University and the International Centre for Translational Eye Research (ICTER) at the Institute of Physical Chemistry of the Polish Academy of Sciences. The phenomenon behind the device was first described in 2014 by an international team that included Komar.
Infrared light can be perceived as visible colour
Two-photon vision occurs when visual pigment absorbs two infrared photons almost simultaneously. Their combined energy is sufficient to stimulate photoreceptors, causing the brain to perceive a visible-light sensation even though the incoming radiation is normally outside the visible spectrum.
One advantage for augmented reality is that the infrared display channel can be separated from the visible light coming from the environment. In the prototype, a dichroic mirror transmits about 96% of visible light while reflecting around 98% of the infrared stimulus. This can reduce the dimming and distortion that affect conventional AR optical systems.
Sharper images across different viewing distances
The researchers also see potential in the greater tolerance of two-photon images to defocus. Results published in Optics Letters in August 2026 showed that participants with stronger accommodation tolerated an average of 6.6 dioptres of defocus for the two-photon image, compared with 4.3 dioptres for a conventional visible-light image.
Work is now focused on making the system mobile. The first applications are expected to be specialised rather than consumer-oriented, including aviation, military systems, space programmes and surgery, where information could be displayed directly in the user’s field of view. Wider adoption will depend largely on further miniaturisation of ultrashort-pulse laser sources.
