"We were able to generate more efficient light in the water-window than in the past," said Emily Gibson, the lead author of the paper. "People have been able to generate small amounts of light in the water window with a laser, but our approach using fibers generates the light more efficiently, allowing you to have enough light to do useful things like take images of cells."
To create the "soft" x-ray beams, the research team led by Kapteyn and Murnane fired a laser through a gas-filled hollow tube called a waveguide. The intense laser light literally rips the atoms of the gas apart, creating both ions and electrons, according to Murnane. The laser beam then accelerates the electrons to very high energies and slams them back into the ions, creating "soft" x-ray light in the process, she said.
Unfortunately, some of the waves can be out of phase, canceling each other out and weakening the strength and coherence of the output beam, she said. However, by modulating the diameter of the guide, Murnane said they can arrange for the laser light and "soft" x-ray light to travel at the same speed along the same path, increasing the efficiency of the process.
As a result, a well-synchronized stream of photons fires out of the system, boosted up to a high-energy, "soft" x-ray wavelength. Many of the most important technologies of the 20th century, such as the Internet and MRI imaging, emerged from the use of electromagnetic radiation ranging from radio waves to the visible region of the spectrum, she said. In recent years fiber optics and photonics have revolutionized communications and created a new global society via the Internet.
'"/>
Contact: Henry Kapteyn
kapteyn@jila.colorado.edu
303-492-8198
University of Colorado at Boulder
2-Oct-2003