*** 9632263 Xie This STTR Phase I propject describes two novel designs for diode-pumped, compact, efficient, blue laser sources. Such sources are needed in many applications including high density optical data storage, laser printing, and free space optical communication. Presently, such compact and efficient sources are not commercially available for these applications. The designs described in this proposal are based on upconversion lasing in rare-earth doped fluorozirconate (ZBLAN) glass fiber. The first is a Pr/Yb co-doped fiber which has previously been demonstrated as a laser operating at red, orange, green and blue wavelengths. The blue laser output power, however, was severely limited due to competing transitions from a common upper laser level. Our solution to the problem is described and will be tested and developed in this proposal. The second upconversion blue fiber laser to be developed in this proposal is based on Tm doped ZBLAN fiber. This laser has also been demonstrated, but lacks a convenient, scalable, diode-based pump source for commercialization. In this project, a novel and efficient pump source will be developed and demonstrated. Prototype laser systems for each of the two designs mentioned will be constructed and tested for future development Potential applications are in the fields of optical data storage, printing applications, free space optical communications, optical display, spectroscopy, flow cytometry, molecular biology, high performance imaging, and semiconductor inspection. ***
