Attainment of a wide wavelength-tuning range in the green and red parts of the spectrum using new laser dyes

A study was made of the lasing characteristics of two new dyes belonging to the naphthalimide and benzanthrone classes, when they were pumped with the second harmonic of ruby laser radiation. The emission wavelength could be tuned over a range of ~100 nm (from 500 to 600 nm in the case of naphthalimide and from 640 to 740 nm in the case of benzanthrone). The use of these compounds in lasers increased the output energy compared with the widely used coumarin 7 and uranin dyes in the green region or cresyl violet in the red region. Moreover, the new dyes ensured a considerably wider wavelength-tuning range.