Flow cytometry, fluorescence spectroscopy, and confocal microscopy commonly utilize continuous wave blue lasers as the illumination source. 488nm Argon-ion gas lasers with power output on the order of 10mW are typically employed. A solid-state alternative light source is desirable due to the inefficiency, short lifetime (less than 5000 hours), cooling fan noise, and large size inherent in gas lasers. Yet, commercial devices have not been developed and implemented due to lack of a suitable nonlinear crystal. Continuing advances in quasi-phasematched (QPM) nonlinear optical materials such as periodically-poled Lithium Niobate will enable development of commercially viable blue lasers. Such materials have high nonlinearity and eliminate walkoff by utilizing non-critical phase-matching (NCPM) now room temperature (less than 100 C) producing high quality beams with efficient conversion. However, at present it is difficult to fabricate device quality crystals with periodically poled features optimized for generating blue light. In this Phase I research plan the periodic poling fabrication process will be redesigned to achieve these optimized features for blue light generation. Finished crystals will be characterized in intracavity frequency doubling laser experiments, and suitability for solid-state blue laser development will be determined. In Phase II prototype lasers based on these crystals will be constructed. PROPOSED COMMERCIAL APPLICATION: The proposed all-solid-state blue laser is useful in confocal microscopy, fluorescence spectroscopy, flow cytometry, DNA sequencing, and capillary electrophoresis. In addition to biomedical instrumentation, blue lasers are desirable in applications such as reprographics, optical data storage and compact disc mastering, laser displays, semiconductor inspection, and holography.