SBIR-STTR Award

Tunability of laser output in the ultraviolet region of the spectrum has typically only been available only with doubled dye lasers. Their toxicity, size and complexity have made them undesirable for many applications, especially in areas where Recent research has demonstrated the feasibility of substitution of trivalent cerium into the colquiriite lattice, which has received considerable attention because of its single ultraviolet emission transition. Laser efficiencies approaching 30% with Ce:LiSAF have been demonstrated, as has tunability spanning from 285 to 297nm. The gain spectrum covers the region from 280 to 320nm, thus optimization of material quality could lead to a UV source which can tune over 4000 cm-1. This research is designed to optimize the Czochralski growth of the Ce:colquiriites in order to produce boules capable of yielding slabs nominally 4x4x80mm. The slabs would be tested in a transverse-pumping geometry to demonstrate moderate average powers over an extended tuning range in the UV. The development of Ce-activated LiSAF/LiCAF will provide the laser community with a crystal that can form the basis of the first, all solid-state, tunable UV laser system.

Lightening Optical Corporation proposes to develop the growth of large crystals of LiSrAlF6 and LiCaAlF6 doped with trivalent cerium ions for transfersely-pumed ultraviolet solid state lasers as a continuation of work initiated during a Phase I SBIR Program. The proposed research plan will include the growth of these two cerium-doped colquiriites in two types of furnaces and with different types of starting materials. A study and comparison of the grown crystals and their spectroscopic properties and laser performances will lead to an optimized set of growth paramters for the production of high optical quality crystals of the better colquiriite host. As th final task for this Phase II SBIR program, the procedure will be scaled up to accommodate the production of large slabs of the selected crystal. The Phase II option will include demonstration of laser performance with the optimized cerium colquiriite host.