Seeing Inside Tissue (IMAGE) California Institute of Technology Caption The Caltech researchers' new technique allows them to focus light deep inside biological tissue. In the experiment, the researchers shined green laser light into the tissue sample seen here in the center. Credit Caltech/Benjamin Judkewitz and Ying Min Wang Usage Restrictions None 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.