Mask for Spiral Laser (image) Australian National University Share Print E-Mail Caption The brass mask used to create the spiral laser beam. The spiral is created by a circular pattern of holes of increasing size. Credit Stuart Hay, ANU Usage Restrictions None 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.