Numerous biomedical analysis techniques utilize laser-induced-fluorescence detection. This provides a high sensitivity analysis tool for biomedical research and clinical diagnosis. The most commonly used laser for these applications is the Ar-ion laser, since it is well matched to the excitation wavelengths of the most widely used dyes. However this laser is less than optimal for these applications: it is fairly large and has low efficiency, so it dissipates much excess heat in the instrument and consumes substantial electrical power. It also has limited lifetime, so regular repair is necessary. This Phase I aims to investigate the feasibility of developing a compact, efficient, robust, long-lifetime laser source that would be a superior, cost-effective replacement for Ar-ion lasers in biomedical instrumentation. It would be based on new InGaAs diode lasers. The near- infrared output of such a diode would he frequency-doubled in a nonlinear crystal to achieve a wavelength of 510 nm, which is optimal for DNA sequencing. We propose to use a resonant doubling cavity to achieve good conversion efficiency. The Phase II follow-on would entail developing a 510 nm source optimized for use in DNA sequencers and other biomedical instruments.
