Stimulated Emission Observed from an Organic Dye, Chloro-aluminum Phthalocyanine

We have observed that when a specific phthalocyanine solution (chloro-aluminum phthalocyanine dissolved in ethyl alcohol) is irradiated by a sufficiently powerful beam from a giant-pulse ruby laser, there occurs intense stimulated emission from the phthalocyanine molecules. The wavelength of this stimulated emission is centered at approximately 0.755 µ. Its spectral half-width was observed to be some 5 cm
⁻¹
.