A nonresonant cavity ringdown diagnostic to measure light attenuation from atmospheric particulate matter at 532- and 355-nm wavelengths is described. The presence of atmospheric particulate is clearly detectable with this technique, as demonstrated by experimental results. The extinction cross section is higher at 355 than at 532 nm, although we were able to purchase significantly higher-reflectivity optics at 532 nm. The expected advantage at 355 nm is thus lost. This new technique is compared with a commercially available instrument, and sensitivity limitations are discussed.

By studying quasi-continuous wave (QCW) operation of a direct LED-Pumped Ce:Nd:YAG solid-state laser, we demonstrate its feasibility as an alternative to direct-diode or flashlamp pumped systems. LEDs emitting at both 460nm and 810nm were used to pump Ce:Nd:YAG laser rod, the former being made possible by the (Ce 3+ ) co-dopant that enables transfer of excitations at 460nm to (Nd 3+ ) ions in the YAG lattice. Comparison of these two pumping schemes has allowed for a thorough analysis of the performance and efficiency of this laser system. QCW output powers as high as 18mJ/pulse are reported, which to the best of our knowledge is the highest output power achieved by an LED-pumped solid-state laser to date.

By studying quasi-continuous wave (QCW) operation of a direct LED-Pumped Ce:Nd:YAG solid-state laser, we demonstrate its feasibility as an alternative to direct-diode or flashlamp pumped systems. LEDs emitting at both 460nm and 810nm were used to pump Ce:Nd:YAG laser rod, the former being made possible by the (Ce 3+ ) co-dopant that enables transfer of excitations at 460nm to (Nd 3+ ) ions in the YAG lattice. Comparison of these two pumping schemes has allowed for a thorough analysis of the performance and efficiency of this laser system. QCW output powers as high as 18mJ/pulse are reported, which to the best of our knowledge is the highest output power achieved by an LED-pumped solid-state laser to date.