Sensors and Electron Devices Directorate Research Areas

High Power Solid-State Laser Science and Technologies

Advisor: Dubinski, Mark. (mark.dubinskiy@us.army.mil 301.394.1821)
Advisor: Merkle, Larry Dean (larry.d.merkle@us.army.mil 301.394.0941)
Adelphi, MD

Key words: Laser materia, Solid-state laser, High power laser, Ceramics, Phase conjugation, Heat spreader, Eye safe, Fiber laser

Research is being pursued on enabling technologies for high power solid-state lasers to meet the needs of the Army and the other armed services. These lasers are more rugged and compact than gas lasers, but have not been scaled to sufficiently high powers while maintaining good beam quality. We are investigating technologies for scalable gain media in Near- and Mid-IR along with advanced , thermal management, and beam quality improvement. These include ceramic gain media, which are as good as single crystals in most regards, but are mechanically stronger, inherently engineerable, and can be scaled to larger sizes. We are pursuing the use of these materials and others at cryogenic temperatures, where key thermal and optical properties are much improved over room temperature. We are particularly interested in laser operation at wavelengths near 1.6 microns in Er-doped solids, since this wavelength range offers much improved eye safety, and where ongoing advances in diodes lasers offer the potential for greatly improved efficiency and reduced thermal distortion. Also of interest are so called ‘low-phonon’ laser materials which offer efficient laser operation in the 3-5 µm wavelength range. Other gain media of interest are fibers, which offer considerable beam quality and efficiency advantages, as well as better device integration, but require innovative designs to enable sufficient power scaling. We are also investigating special materials and laser architectures to promote heat removal from laser gain media and to further improve beam quality, beam correction and beam combining techniques based on stimulated light scattering (Brillouin and Raman).
Our laboratories have a range of laser and spectroscopic tools for these studies. These include several types of diode lasers and diode arrays for efficient pumping of laser materials and a range of laser cavity designs to test materials and thermal management approaches. We also have up-to-date spectrometers for absorption and emission spectroscopy, and cryostats for both laser and spectroscopic studies as a function of temperature.

Reference
M. Dubinskii, J. Zhang, V. Ter-Mikirtychev: Optics Letters Vol. 34, 1507-1509, 2009
N. Ter-Gabrielyan, L. D. Merkle, E. R. Kupp, et al.: Optics Letters 35, 922-924, 2010