A living laser
It sounds like something out of a comic book or a science fiction movie — a living laser — but that is exactly what two investigators at the Wellman Center for Photomedicine at Harvard-affiliated Massachusetts General Hospital (MGH) have developed. In a report that will appear in the journal Nature Photonics and is receiving advance online release, Wellman researchers Malte Gather and Seok-Hyun Yun describe how a single cell genetically engineered to express green fluorescent protein (GFP) can be used to amplify the light particles called photons into nanosecond-long pulses of laser light. “Since they were first developed some 50 years ago, lasers have used synthetic materials such as crystals, dyes, and purified gases as optical gain media, within which photon pulses are amplified as they bounce back and forth between two mirrors,” says Yun, corresponding author of the report and an associate professor of dermatology at Harvard Medical School (HMS)....