Direct Timing of the Relaxation from Selected Excited States; Beta-Naphthylamine

Abstract

The fluorescence of β‐naphthylamine vapor in the low‐pressure region was timed directly using a high‐speed laboratory light modulator. Emission was from defined, and variable quantum states initially pumped with high‐intensity monochromatic light. The energy of irradiation was swept over a range of 10 000 cm⁻¹, encompassing two excited electronic manifolds. The results then constitute a direct timed measurement of the relaxation from individual vibronic states as the energy of excitation is continuously increased. This is then a spectrum of vibronic lifetimes which is discussed in terms of various theories for electronic relaxation.