Persistent spectral hole-burning of pseudoisocyanine bromide J-aggregates

Abstract

We have examined the hole formation profiles of the upper exciton band in J-aggregates of pseudo-isocyanine bromide/water-ethyleneglycol system by using DC-light laser or nanosecond pulsed laser. In the former case, a clear zero-phonon hole was formed with a width of 0.36 cm −1. Assuming negligible contributions of the dephasing by phonons, the homogeneous width of the one-exciton state is lifetime-limited in nature and T 1 ∼ 28 ps. On the other hand, a novel feature of the dispersive lineshape of holes was found in the pulse mode burning from the initial stage of irradiation. It is presently ascribed as a result of the excitation of the two-exciton band which is inherent to the excitonic state with large coherence length.