Q&A

NASA Tech Briefs, Mar 2004 by Blackwell, Tim

The Who's Who at NASA column in NASA Tech Briefs' January issue (available on page 14 or online at www.techbriefs.com/whoswho) discussed thin-disk, high-power lasers - a key component of laser research being led by NASA's Marshall Space Flight Center (MSFC) in Alabama. This month's Q&A provides additional insight into this advancing technology.

What are the advantages and applications of thin-disk laser architecture?

One of MSFC's laser designs, the thin disk, is based on original technology developed by Dr. Giesen at the University of Stuttgart's Institute for Laser Research, in Germany (see illustration). The small-volume large-area gain medium, or thin disk, design shows considerable promise for high efficiency, compact, and lightweight laser packages, which have the qualities and high power of much larger and more cumbersome laser systems.

This thin-disk technology has recently been incorporated into commercial industrial welding and cutting equipment, demonstrating the efficiency and robustness of the technology. The elegant pump cavity design leads to more output beam efficiency with an overall reduction in the system-level power requirements, which may prove ideal for power beaming and space applications.

One of our current research objectives, for instance, is to develop, build, and test a multikilowatt solid-state laser suitable for space applications using thin-disk technology, and to demonstrate optical power transmission over a distance. We are supporting this development with a variation of gain materials and pump methodologies to support the development of high-power, spacequalified lasers with the ability to be scaled to many tens of kilowatts in a compact and lightweight package. These technologies possess the potential to produce viable high-power laser systems in the shortest amount of time. This technology can also be packaged into extremely compact low power output (a few tens of watts) lasers for use in such applications as might be envisioned on the International Space Station, or for other microgravity or space research.

This technology effort may also eventually produce laser devices capable of providing on-orbit propulsion and planetary exploration power. Thin-disk lasers may reduce the cost of such efforts by reducing the amount of fuel necessary to be carried on the vehicle, or possibly provide the vehicle with a virtually unlimited operating life without fuel limitations.

The development of ultrastable lasers may also be facilitated by this work. Ultrastable lasers will enable missions requiring long distance measuring or pointing capability (such as in a free flyer or formation flying concept), and scenarios requiring the use of compact, lightweight, and highly efficient lasers (such as deep space communication or power transmission missions).

Are you interested in submitting a question or providing expertise for PTB's new Q&A column?

Contact Ashli Riggs, editor, at ashli@abpi.net

Tim Blackwell is an advanced laser systems engineer far the University of Alabama, located at the National Space Science and Technology Center (NSSTC) in Huntsville, Alabama. he can be contacted at Timothy.S.Blackwell@nasa.gov or (256) 961-7036.

The NSSTC is a research partnership between NASA's MSFC, Alabama universities, federal agencies, and industry. Visit www.nsstc.org for more information.