A holographic waveguide based eye tracking device

Area of Science:

• Optics and Photonics
• Biomedical Engineering
• Ophthalmology

Background:

• Eye tracking is crucial for diagnosing oculomotor disorders and enabling human-computer interaction.
• Existing eye trackers can be bulky or intrusive, limiting their use in real-life scenarios.
• Developing compact, see-through wearable eye trackers is a significant technological challenge.

Purpose of the Study:

• To demonstrate the feasibility of using a holographic waveguide for eye tracking.
• To develop and validate a prototype eye tracker based on holographic waveguide technology.
• To assess the performance and potential of this technology for wearable applications.

Main Methods:

• A custom holographic waveguide with integrated in- and out-couplers was fabricated on a glass substrate.
• Diffractive optical elements were used as an optical collimator within the in-coupler.
• Eye images were captured and guided to a processing unit; pupil center (PC) and corneal reflex (CR) vectors were used for eye position computation.
• A 3D printed model eye was used for prototype validation.

Main Results:

• The prototype demonstrated a linear relationship between angular eye position and the PC/CR vector across 60 horizontal and 40 vertical degrees.
• The eye tracker achieved a tracking accuracy of 0.72 degrees and a tracking precision of 0.50 degrees.
• The holographic waveguide successfully guided eye images to a remote processing unit.

Conclusions:

• Holographic waveguide technology is a feasible platform for developing wearable eye trackers.
• The developed prototype shows promising accuracy and precision for eye tracking.
• Further development could lead to compact, see-through eye trackers for continuous monitoring and diagnosis of oculomotor disorders.