The performance of the compact, efficient, highly stable all solid-state ultraviolet laser source created in the Phase I effort , where it was characterized in preliminary cytometry and confocal microscopy evaluation studies, will be further developed to obtain higher power and shorter wavelength. This will permit the source to be of use in a broader class of applications including cytometry that uses shorter wavelength dyes and higher throughput applications such as cell sorting and DNA analysis. A recent extension of this basic laser technology promises to make practical new laser sources that have very short pulses and high repetition rates. This could become an important, if not an enabling, tool for research and for development of commercial instruments that require high peak power for two-photon excitation, such as two-photon microscopy and two-photon 3D microfabrication, and for new optical imaging diagnostics. The proposed Phase II work focuses on applications in cytometry and UV and two-photon microscopy where it is believed that these new laser sources might catalyze the development of new techniques and make these important but expensive diagnostics more widely available. PROPOSED COMMERCIAL APPLICATIONS: It appears likely that such laser sources will be able to replace gas discharge lasers in a host of applications, including laser induced fluorescence, substantially reducing the cost, size and complexity of biotechnology instrumentation that requires intense light at near ultraviolet wavelengths. Significant commercial markets exist for deep red and ultraviolet laser sources that can be gracefully integrated into cytometers and modern microscopes.