Near-Ultraviolet Lasing Dyes. Part 1. Search for New Dyes and Summation of Results.

摘要

The object of this investigation was to obtain improved laser dyes with outputs within the 380- to 400-nm region having low thresholds, high slope efficiencies, high photochemical stabilities, and operating under long-pulse flashlamp excitation. A combined search, synthesis, and test program examined four approaches: (1) substituent effects on known efficient bicyclic dyes such as the coumarins, (2) aza-substitution in the benzo-ring of such bicyclic compounds, (3) a class of monocyclic dyes, and (4) other miscellaneous compounds having strong fluorescence in or near the target region. Close to 70 new compounds were prepared and about half of the materials examined lased under short-pulse flashlamp excitation within the 350- to 450-nm range. Of six dyes operating within the 380- to 400-nm target region only two, 7-dimethylamino-1- methyl-4-methoxy-8-azaquinolone-2 and 7-hydroxy- 4-methyl-8-azaquinolone-2, satisfied specifications, although they were not as efficient as the coumarins.