From little seeds do laser beams grow

Compact lasers producing high-quality beams of light could open a plethora of applications in imaging, microscopy and the probing of matter. Research published this week in Nature Photonics makes this dream a reality.

For over 20 years scientists have been producing laser light in the extreme UV part of the spectrum — that is, at wavelengths from about 1 nm to 30 nm — using plasma (or ionized gases).

With the goal of making these lasers as compact as possible, Jorge Rocca and colleagues use a technique known as injection seeding to create beams of light with waves that are in step (vibrate together) in both space and time. They take a low-power beam of light, pass it through a dense plasma and use it to produce a more powerful, amplified beam of light at the right wavelength. The resulting pulses of light are about 1 ps long, have wavelengths less than 20 nm, and can be created using a practical, table-top laser.

Rocca and co-workers manage to generate light with a wavelength around 13 nm, a key wavelength used by computer chip manufacturers, and which has implications for the fields of imaging and computing.

Phase-coherent, injection-seeded, table-top soft-X-ray lasers at 18.9 nm and 13.9 nm

Y. Wang, E. Granados, F. Pedaci, D. Alessi, B. Luther, M. Berrill & J. J. Rocca

Published online: 20 January 2008 | doi 10.1038/nphoton.2007.280

Abstract | Full text | PDF

Author contact:

Jorge Rocca (Colorado State University, Fort Collins, Colorado, USA) Tel: +1 970 491 8371; e-mail: rocca@engr.colostate.edu