Dye laser system pumped by the 2nd harmonic wave of $Nd^{+3}$-YAG laser is designed, fabricated, and the operational characteristics are investigated.
First, $Nd^{+3}$-YAG laser system is constructed and its performance is investigated. In the design, the optimum reflectance for the output coupler is computer simulated, and it is found the reflectance of 35% gives the maximum output power of the Q-switched $Nd^{+3}$-YAG laser.
In the second stage, KDP crystal is grown for the second harmonic generation of the Q-switched $Nd^{+3}$-YAG laser output wave. Output characteristics of the SHG wave is investigated experimentally, and the conversion efficiency of the KDP crystal is found to be 7.1%.
Finally, dye laser system pumped by the SHG is constructed. The dye used in this experiment is rhodamine-6G and its concentration is $5\times10^{-3} mol/l$ solution in ethylen-glycol. The tuning range of rhodamine-6G dye laser is found to be 5775Å-6114Å. The diffraction limited linewidth of the wave selector (beam expander +grating) is 1.09Å. For the laser oscillation, however, the limited linewidth becomes generally reduced and is measured to be 0.086Å in this experiment. This reduction of the linewidth is due to the fact that oscillations in the cavity enhance the intensity in the center wavelength region due to higher gain.
