Theoretical investigations in femtosecond coherence spectroscopy

M. Joffre

S. H. Lin, Benjamin Fain, C. Y. Yeh

We present a theory of time-resolved emission spectroscopy in the femtosecond region. It is shown that a femtosecond time-resolved emission spectrum consists of the contributions from the population and coherence of the system. Theoretical expressions for describing femtosecond time-resolved emission molecular spectra based on the use of the adiabatic approximation are derived. Detailed numerical calculations have been carried out to show the effect of the time evolution of the population and coherence on the time-resolved emission spectra.

Dai‐Sik Kim

Jing Lu, Soo‐Y. Lee, Kangnian Fan

Lap Van Dao, My Thi Tra Do, Peter Hannaford

We present a new multidimensional spectroscopy technique based on femtosecond spectrally resolved 2colour 3-pulse photon echoes for investigating of the carriers dynamics in the photonic materials such as semiconductor doped glass and porous silicon. The use of different colours and polarisations for the pump and probe pulses together with spectral analysis of the photon echo signals allows separation of the dynamics of electrons and holes.

JunWoo Kim

Recent advances in single-photon femtosecond spectroscopy have highlighted the power of entangled photons in probing the properties of materials, previously inaccessible through semiclassical spectroscopic approaches. In this study, we theoretically propose a new single-photon-based femtosecond time-resolved spectroscopy technique termed single-photon transient stimulated emission (SP-TSE). SP-TSE not only enables the selective investigation of singly excited superposition states but also harnesses the quantum mechanical nature of photons for the efficient data acquisition of transient responses, thereby supporting the feasibility of experimental realization of SP-TSE. The key aspect of SP-TSE is the selective detection of two-photon states produced through stimulated emission using coincidence counting techniques. Our theoretical framework, supported by numerical simulations, demonstrates the efficacy in capturing the pure decoherence dynamics of a model molecular cavity, highlighting its potential to reveal quantum mechanical properties that are difficult to observe with semiclassical femtosecond time-resolved experiments.