Needle Beam -- Explanatory Diagrams (image) Harvard University Caption Top: This shows a micrograph and diagram of the metallic gratings that produce the needle beam. Bottom: This is an approximation of the experimental setup. A laser is focused from the glass substrate side onto the device. Once the non-diffractive surface wave is created, detailed information on its intensity distribution is gathered using an ultrahigh-spatial-resolution near-field scanning optical microscope. Credit Images courtesy of Patrice Genevet. Usage Restrictions None 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.