An Invisible Waveguide Being Written Via Laser into a Smartphone's Display Glass (image) The Optical Society Share Print E-Mail Caption An invisible waveguide (pathway for light) being written via laser into a smartphone's display glass is shown. The waveguide is a horizontal line from the left side of the screen, but it cannot be seen with the naked eye. Credit Optics Express Usage Restrictions Include caption & credit Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.