SBIR-STTR Award

This Small Business Innovation Research (sbir) Phase I project will evaluate a fluoride crystalline material; NaYF4 (NYF) as a host for laser diode pumped laser. Nd:NYF has superior spectroscopic properties to Nd:YLF and Nd:YAG, crystals that are widely used in commercial laser diode-pumped lasers and has comparable properties to Nd: YVO4, a material more efficient than either YAG or YLF. When a combination of Yb and Er dopants are incorporated to NYF, this material shows great promise for an upconversion phosphor. AC Materials Inc. proposes to develop enabling technology for production of high optical quality NYF crystals for laser applications. AC Materials has conceived an innovative approach to grow uniformly doped single crystals of non-stoichiometric fluoride materials. The Phase I program will involve growth of single crystals also by the Top-Seeded Solution Growth technique, which will produce samples of enough size and quality for laser evaluation. Material properties that are relevant to the application of NYF as a laser will also be measured. Production of granular rare-earth doped NYF will enable its evaluation as a phosphor material. The commercial market of this material is two fold: for a replacement material used as the bases for diode pumped lasers and displays. During Phase I, the proposer will work with OEM manufactures to incorporate this material into their products. This material shows great promise to replace current materials used in the industry.

This Small Business Innovation Research (SBIR) Phase II project will focus on improving solution growth of Nd and Yb,Pr-doped NaYF4 single crystals. Two alternate techniques are proposed: top seeded solution growth and traveling solvent zone. Phase I results indicate that spectroscopically Nd:NYF is superior to YAG and YLF and as good or better than YVO4 as a laser diode-pumped laser; and that Yb,Pr:NaYF4 is a 1.3 micron emitter with favorable properties for use in telecommunications. In a parallel effort to crystal growth, laser evaluation of NYF will continue through laser tests and by measurements of NYF's thermo-optic properties. In Phase I a very efficient single phase green emitter Yb,Er :NYF phosphor was demonstrated. A second thrust of this Phase II effort will then be to develop synthesis processes of granular doped NYF materials for their use in 2-D and 3-D displays. Combinations of Yb,RE-doped NYF will be prepared to extend the range of colors to red and blue. Nd:NYF is seen as a superior material to YLF and YAG for compact diode pumped lasers and an economical alternative to Nd:YVO4 currently used. Yb, Pr: NYF can be used as amplifiers for telecommunications in the important 1.3 micron wavelength range. NYF phosphors, dispersed in plastic hosts can be used in 2 and 3-D transparent displays for head mounted applications such as air traffic control, medicine, autos and aircraft.