Development of New Mid-Infrared Ultrafast Laser Sources for Compact Coherent X-ray Sources

Bright, coherent light sources in the soft x-ray region of the spectrum are useful for a variety of applications of interest to DoE. However, for many applications, such as nanometer-scale microscopy in the ¿water window¿ region of the soft x-ray region of the spectrum (300-500 eV photon energy), or for magnetic materials imaging (¿ 800eV photon energy), only large-scale synchrotron facilities are currently capable of generating the required flux. The implementation of small-scale table-top sources of bright coherent soft x-rays would greatly expand the potential impact of technologies developed at synchrotrons, allowing the source to be brought to applications in science and industry. One promising approach that addresses this need is to coherently up-convert laser light to short wavelengths through the process of high-order harmonic generation. This technique is currently used to generate bright, ultrashort-pulse light in the extreme-ultraviolet region of the spectrum, at ~50-100 eV photon energies. However, the flux generated by this technique is not currently sufficient for most applications. This project will investigate a new generation of ultrashort-pulse lasers that operate in the mid-infrared, at wavelengths ~3x longer than current generation ultrafast lasers. Commercial Applications and other Benefits as described by the awardee: The technology should find use in the development of tabletop, soft-x-ray microscope technology, allowing for tomographic and holographic imaging of single cells with <20 nm resolution, and for materials imaging. The source also should be uniquely suited to the study of molecular dynamics in organic molecules, chemical sensing, and catalytic reactions. Finally, the mid-IR laser technology itself should find broad application in the chemical sciences and for remote sensing applications.