PICOSECOND FLUORESCENCE STUDIES BY INTRACAVITY GAIN SPECTROSCOPY IN AMODELOCKED DYE-LASER

This article presents measurements which combine modelocking technique with intracavity spectroscopy. To test this approach, a sample (10(-5 ) m ethanolic solution of 1,4-dihydroxyanthranquinone) was inserted in a modelocked Ar+ ion laser and probed by intracavity pulses of a sync hronously pumped dye laser. The probing of the sample results in an am plification of the dye laser output. Maximum output was measured if th e pulses of the dye laser temporally overlapped with those of the Arion laser inside the sample. Under this condition, the spectral laser intensity was shaped by the spectrum of stimulated fluorescence which originated from a molecular vibronic state populated by pump laser exc itation.