Scientists Created Laser Light by Using Living Biological Material

For the first time laser light was created by scientists, using living biological material; a single human cell and some jellyfish protein. Seok-Hyun Yun, an optical physicist at Harvard Medical School and Massachusetts General Hospital in Boston created the living laser with his colleague Malte Gather. This was the first time that biological materials were used to build a laser and generate light from something living.

The criteria for building a laser

Building a laser requires two things; (1) a lasing material that amplifies light from an external source (a gain medium) and (2) an arrangement of mirrors (an optical cavity), which concentrates and aligns the light waves into a tight beam.
Before the creation of living laser, the gain medium has only been made from non-biological substances such as doped crystals, semiconductors or gases. But in living laser, the researchers used enhanced green fluorescent protein (GFP). Green fluorescent protein (GFP) makes jellyfish bioluminescent, which is used extensively in cell biology to label cells.
Seok-Hyun Yun and his team engineered human embryonic kidney cells to produce GFP, then placed a single cell between two mirrors to make an optical cavity just 20 micrometres across. When they fed the cell pulses of blue light, it emitted a directional laser beam visible with the naked eye and the cell wasn't harmed.
The width of the laser beam is tiny and fairly weak. It is brighter than natural jellyfish fluorescence, with a beautiful green colour.

How the technology can be used

•    Biologists could turn cells of interest into lasers to study them.
•    The light produced has a unique emission spectrum related to both the structure of the cell and the proteins inside it. By analysing the pattern one can get some idea of what is happening inside the cell.
•    Doctors shine lasers into the body to gather images or to treat disease by attacking cells. Lasers could instead be generated or amplified inside the body, where they could penetrate the relevant tissues more deeply.