In the near-infrared, visible, and ultraviolet regions, continued support of lasers in individual investigators' laboratories is the highest priority.
The development of nonlinear materials for extending the wavelength capabilities of laboratory lasers deserves support in both universities and industry (e.g., through the Small Business Innovation Research program). Support for this activity should receive a high priority, as even a modest investment is likely to have a considerable impact on scientific research.
In the near-infrared, visible, and ultraviolet regions, support for additional free electron lasers should receive relatively low priority with respect to support of conventional lasers and with respect to support for free electron lasers in other wavelength regions.
In the vacuum ultraviolet (VUV) and extended ultraviolet, the region from approximately 200 nm to 10 nm, laboratory lasers become increasingly inefficient. There are important scientific needs for radiation in this region, including photodissociation, single-photon ionization detection, photoelectron spectroscopy of dilute species, and pump-probe photoemission.
Modern third-generation synchrotrons will cover the vacuum ultraviolet and extended ultraviolet regions well and will provide opportunities to explore much new scientific research in this wavelength region.
There are currently no free electron lasers that operate in this region. The construction of a device should be possible with some additional research and development. It may be possible to construct a large VUV free electron laser facility now, since most of the component pieces have been demonstrated, but construction of a VUV free electron laser using current technology would cost on the order of tens of millions of dollars and involve some risk.
A user community for a VUV free electron laser is not well developed at this time but could grow with the exploition of third-generation synchrotron sources, demonstrating proof-of-principle experiments.