Single-photon excitation of coherent states: a bridge from the particle to the wave character of light

Bellini M., Zavatta A., Viciani S.

Alessandro Zavatta, Silvia Viciani, Marco Bellini

When a single quantum of electromagnetic field excitation is added to the same spatiotemporal mode of a coherent state, a new field state is generated that exhibits intermediate properties between those of the two parents. Such a single-photon-added coherent state is obtained by the action of the photon creation operator on a coherent state and can thus be regarded as the result of the most elementary excitation process of a classical light field. Here we present and describe in depth the experimental realization of such states and their complete analysis by means of a novel ultrafast, time-domain, quantum homodyne tomography technique clearly revealing their nonclassical character.

Zavatta A., Viciani S., Bellini M.

Bellini M., Zavatta A., Viciani S.

We present the experimental generation of a new class of non-classical light states and their complete phasespace characterization by quantum homodyne tomography. These states are the result of the most elementary amplification process of classical light fields by a single quantum of excitation and can be generated by the process of stimulated emission of a single photon in the mode of a coherent state. Being intermediate between a single-photon Fock state and a coherent one, they offer the unique opportunity to closely follow the smooth evolution between the particle-like and the wave-like behavior of the light field and to witness the gradual change from the spontaneous to the stimulated regimes of light emission.

Seokhyun Jang, Kisik Kim

We investigate the connection between the particle nature of light and its nonclassical character. When we can associate a precise number of photons, in some sense, to a particular state of light, the state possesses a full particle nature. We show that whenever a complete particle nature emerges in the state of light, the corresponding nonclassical measure becomes unity, and the state becomes maximally nonclassical.

Thomas P. Pearsall