Quantum blackbox model for electro-optical phase modulation

J. Capmany, Carlos R. Fernández‐Pousa

We present, for the first time, a blackbox model characterizing the quantum optical phase modulation operation in terms of a unitary scattering operator which excludes the unphysical negative frequencies.

A.G. Tam, Kerry James Hinton, Peter M. Farrell +1 more

Stephen Mark Barnett, David Thomas Pegg

J. Capmany, Carlos R. Fernández‐Pousa

We present a quantum model for electro-optic amplitude modulation, which is built upon quantum models of the main photonic components that constitute the modulator, that is, the guided-wave beamsplitter and the electro-optic phase modulator and accounts for all the different available modulator structures. General models are developed both for single and dual drive configurations and specific results are obtained for the most common configurations currently employed. Finally, the operation with two-photon input for the control of phase-modulated photons and the important topic of multicarrier modulation are also addressed.

Noriaki Horiuchi

D. B. Horoshko, M. M. Eskandary, S. Ya. Kilin

We develop a quantum model of a traveling-wave electro-optical phase modulator by considering a parametric interaction of the optical and radiofrequency waves in the modulator medium by means of the electro-optic effect. The model includes a possible dispersion of the modulator medium in the optical domain. In the case of negligible dispersion, we derive a simple analytic expression for the evolution operator of the optical field, which has been proposed previously in the literature on the basis of an analogy to classical field transformation. We study by means of a perturbative approach the influence of small dispersion on the field evolution operator and formulate conditions of negligibility of modulator dispersion. We demonstrate the signature of dispersion in phase modulation: breaking the symmetry of sidebands with respect to the mean photon number. We obtain the law of transformation of a multimode coherent state by a phase modulator, which is important for understanding the structure of signal states in quantum cryptographic schemes utilizing phase modulation of coherent optical beams.