Laser hope for atmosphere

Since 1975, global surface temperatures have increased by approximately 0.9 degrees Fahrenheit, a trend that, according to Nasa, has taken global temperatures to their highest level in the past millennium.

Statistics such as these have prompted scientists from The John Hopkins University and Nasa’s Goddard Space Flight Centre to join forces to develop a powerful fibre-optic laser system to monitor the atmosphere.

The laser system, mounted inside a satellite and envisioned to be no larger than a laptop computer, will fire an ultraviolet beam towards Earth, striking molecules in the atmosphere.

The beam will bounce off molecules, such as ozone and carbon dioxide, and carry information about the condition of the atmosphere back to the satellite.

Jin Kang, an assistant professor in John Hopkins’ Department of Electrical and Computer Engineering, will create the ultraviolet light source based on fibre-optic laser technology. Engineers at Goddard will fabricate a durable housing designed meet the demands of space travel.

It is hoped the laser device will become the critical component of a LIDAR system, a variation of radar that uses light instead of radio waves.

In this system, light beams are directed at the atmosphere. When the beams strike gas molecules, they bounce back, carrying a wavelength absorption ‘fingerprint’ containing information about the identity of gases in the atmosphere and their density.

The engineers from Johns Hopkins and Goddard aim to finish building their fibre-optic laser device within three years. Afterward, the same team hopes to incorporate the laser into a larger research instrument that could be launched into space within a few years.

On the web at www.gsfc.nasa.gov