Stimulated Emission Enhancement Using Shaped Pulses

Abstract

Controlling stimulated emission is of importance because it competes with absorption and fluorescence under intense laser excitation. We performed resonant nonlinear optical spectroscopy measurements using femtosecond pulses shaped by π- or π/2-step phase functions and carried out calculations based on density matrix representation to elucidate the experimental results. In addition, we compared enhancements obtained when using other pulse shaping functions (chirp, third-order dispersion, and a time-delayed probe). The light transmitted through the high optical density solution was dominated by an intense stimulated emission feature that was 14 times greater for shaped pulses than for transform limited pulses. Coherent enhancement depending on the frequency, temporal, and phase characteristics of the shaped pulse is responsible for the experimental observations.

Quantum coherent control of H3+ formation in strong fields

“…QCC has been used to control two-and three-photon transitions in atoms and molecules in the gas phase 5 and in the condensed phase. 6 When the phase step is only π/2, one finds that the magnitude of the QCC is half of that observed for the π-step, noting that there is no difference if the step is positive or negative [ Fig. 1(b)].…”

Manipulation of matter with shaped-pulse light field and its applications

“…However, it was demonstrated that the phase information used to excite the samples selectively could survive after passing through tissue, and decoherence and optical resolution were not affected by pulse shaping [177]. Shaped laser with a πphase step is transmitted through optically dense Indocyanine Green sample, and an enhancement of stimulated emission up to 14 times, compared to that from the transform-limited pulse, was observed [178]. Potential applications were proposed, like the transmission of signals through absorbing media or controlling photodynamic therapy (PDT).…”

Observation of a Long‐lived Electronic Coherence Modulated by Vibrational Dynamics in Molecular Nd3+‐Complexes at Room Temperature

“…150 fs was measured in a single CsPbBr 3 perovskite quantum dot, whereas for non‐perovskite quantum dots at room temperature coherence times in the tens of femtoseconds range are observed (e. g. 75 fs in colloidal CdSe) [25] . In solutions of dye molecules, coherent third‐order response was measured up to 180 fs [26] . Especially in a solution at room temperature, the interaction with the solvent molecules leads to these short lifetimes of the electronic coherence, while at a lower temperature, one might expect an increase of the lifetime.…”