Laser Beams (IMAGE) University of Vienna Caption Long-exposure photo of laser beams with a twisted wavefront. The beams have holes in the middle due to destructive interference at the center of the twists. Credit Copyright: Faculty of Physics, University of Vienna Usage Restrictions The image may only be used with appropriate caption or credit. License Licensed content 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.