This Small Business Innovation Research Phase I project will develop visible fiber lasers and amplifiers. The advantages of these devices include very high efficiencies, high gain, direct diode laser pumping, high spatial mode quality, room temperature operation, and the fiber geometry inherently avoids thermal problems. The project will leverage research on energy transfer between rare-earth ions in low phonon energy glasses, color-center formation in crystalline hosts, and diode-pumped solid state lasers. A chemically stable, high power, continuous wave visible laser will be developed. There are a broad range of applications for visible fiber lasers and amplifiers, including multi-color displays and printing.