High-Power, 3-Micron, Fiber-Based Laser System

The Navy has identified tactical applications for 3000-nm-wavelength-region lasers, which feature very high efficiency in coupling laser energy to water. This is the result of the most intense infrared absorption band for liquid water, which has a broad peak centered at 2900 nm, with an absorption coefficient of 10000 /cm. Development of lasers in the region has, in the past, been driven primarily by medical applications that rely on the absorption by tissue for the 2800-2900-nm wavelength range, a result of the high water content of most tissues. The Navy requires average powers exceeding 100 W and high beam quality, and this proposal addresses how this may be accomplished. The work we propose centers on the development of fiber lasers, doped with Er ions.