Laser singulation of high refractive index glasses for augmented reality waveguides

As Augmented Reality (AR) and Mixed Reality (MR) devices emerge and promise to revolutionize the way in which we perceive and interact with the world, the continued focus on the low-cost, high-volume manufacturing of the waveguides that underpin the technology is required. A significant challenge is the singulation of the high refractive index glass wafers into individual waveguides without affecting the sensitive optical components (e.g., gratings) on them. The laser nanoPerforation glass singulation process developed by Corning is well-established in multiple industrial applications and has been successfully deployed into high-volume manufacturing for AR waveguide devices. A detailed investigation into optimizing the edge strength of 0.5 mm thick Corning high refractive index glasses (n=1.7-2.0) reveals values in the range of 130-150 MPa (B₁₀). By applying fundamental process understanding and further optimization to Corning 0.3 mm Augmented Reality Systems (ARS) 2.0 glass, an initial demonstration of edge strength values up to 202 MPa (B₁₀) is realized.