NASA SBIR 2003 Solicitation

FORM B - PROPOSAL SUMMARY


PROPOSAL NUMBER: 03- II E1.02-8698
SUBTOPIC TITLE: Lidar Remote Sensing
PROPOSAL TITLE: Efficient High Power 2 micron Tm3+-Doped Fiber Laser

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Shibin Jiang
jiang@npphotonics.com
9030 S. Rita Road
Tucson, AZ 85747-9102
(520)799-7407
U.S. Citizen or Legal Resident: Yes

TECHNICAL ABSTRACT (LIMIT 200 WORDS)
This proposal is for the development of new Tm3+ doped germanate glass fibers for efficient high power 2-micron fiber lasers capable of generating an output power of up to hundreds watts. We propose to use Tm3+ doped germanate glass fibers because silica glass fiber is not the ideal host for lasers at wavelength of 2-micron and longer. Germanate glass exhibits lower phonon energy compared to silica glass, increasing the quantum efficiency of 3F4 level of Tm3+ ions. Importantly, Tm3+ can be highly doped into germanate glasses, which results in so called cross-relaxation, dramatically improving the quantum efficiency. We will develop double-clad single mode germanate glass fibers with greater than 6wt% Tm3+ concentration to take full advantages of this Tm3+ cross-relaxation process, developing highly efficient fiber lasers at 2-micron. This type of fiber laser is useful for LIDAR applications, can also be used to pump Ho3+ doped crystals to generate extremely high power 2-micron lasers.

POTENTIAL NASA COMMERCIAL APPLICATIONS (LIMIT 100 WORDS)
This efficient 2-micron fiber laser can be used for medical applications to replace currently widely used CTH:YAG laser. Generally, fiber lasers outperform solid-state lasers in reliability, compactness, and efficiency.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (LIMIT 100 WORDS)
This fiber laser can be used to pump Ho doped crystals to generate extremely high power 2-micron lasers, which are generally used for LIDAR applications in NASA. The wavelength of Tm3+ fiber laser can be tuned to Ho3+ absorption peak of 5I8 ?5I7 transition, minimizing any detrimental up-conversion. The developed Tm3+ doped single mode fiber can also be used to build single frequency fiber laser with extremely narrow linewidth and long coherence length, which can be used as the seed laser for NASA's 2-micron solid-state laser.