16.12.2025 A prototype is being created in ICTER’s laboratories that may redefine how we build augmented reality. The team led by Dr. Eng. Katarzyna Komar is developing AR glasses that use two-photon vision. This mechanism enables bright, sharp, and high-contrast images without complicating the optics and without the typical limitations of today’s solutions.
Although augmented reality has been heralded for years as the next technological revolution, the market is still waiting for a device that will truly convince users. Optics remain the biggest challenge: one must simultaneously preserve a clean, unobstructed view of the environment while inserting digital content that is bright and clear enough to compete with natural light. This requires complex waveguide optics and light sources with a high dynamic range. On top of that comes the accommodation-convergence conflict – a well-known effect to anyone who has tried using VR or AR headsets for extended periods.
Two-photon vision makes it possible to approach this problem from a different angle. Normally, light with a wavelength in the 800-1300 nm range is invisible to us, because its photon energy is too low to stimulate the photoreceptors in the retina. It turns out that if the light takes the form of very short pulses, the photoreceptors absorb two photons simultaneously, and the combined energy of these photons is enough to stimulate the photoreceptors. In such a case, our brain perceives a normal visible image, even though it was physically generated by light from an entirely different spectral range.
Why can two-photon vision change AR?
In ICTER’s laboratories, researchers have shown that such stimuli can be extremely bright, reaching an equivalent luminance of even several hundred candelas per square meter. Moreover, brightness here increases not linearly but quadratically as the power of the light source increases, which provides designers with a completely new range of possibilities. Two-photon images also maintain very high contrast-often better than classical one-photon stimuli – and, crucially, they are perceived as always sharp, regardless of whether we focus our gaze on near or far distances. This means the accommodation-vergence conflict may no longer be a technological barrier.
One of the most surprising effects of this technology is the ability to generate the purple color from a single monochromatic light source. In traditional displays, this is impossible because purple arises from a combination of red and blue. It turns out that pulsed light in the 850-950 nm range is perceived both as one-photon and two-photon simultaneously, as red and blue, respectively, which effectively produces the purple color.
The AR glasses project based on two-photon vision, led by Dr. Eng. Katarzyna Komar, is an attempt to translate the knowledge gained in the optical laboratory into a device that can realistically be worn on the head. Within a year, a prototype was created that combines a MEMS scanner, tunable optical elements, a fiber-based laser path, and software that synchronizes all components in real time. The entire system was placed in a lightweight optometric frame whose task is not only to hold the device on the head but also to maintain a precise distance and position relative to the eye.
The technology uses a laser previously developed by Dr. Eng. Dorota Stachowiak and her collaborators at Wroclaw University of Science and Technology – a femtosecond erbium-doped fiber laser tunable from 872 to 1075 nm, perfectly suited to the needs of two-photon vision research.
What’s next?
The project concluded in October 2025, but the key tests are only just beginning. The team is now working on refining the mechanical design and developing procedures that will allow the glasses to be precisely fitted to different users. The next step will be measurements of contrast sensitivity and brightness matching – performed for the first time not in a stationary laboratory system, but using the AR glasses.
In the longer term, plans include redesigning the optics, considering the use of curved dichroic elements, creating a binocular version, and developing and miniaturizing custom laser sources optimized specifically for two-photon image display.
A new path for augmented reality
The work of Dr. Eng. Katarzyna Komar and her team shows that two-photon vision may become the missing link in augmented reality technology. It is an approach that does not require optical compromises, allows for high brightness and high contrast, and at the same time overcomes the human-eye-related limitations that this technology has struggled with.
The project is funded by the Foundation for Polish Science under the Proof of Concept FENG program, co-financed by the European Union, and the team’s research is also supported by NCN grants and the Teaming for Excellence program.
