Spontaneous Parametric Down-Conversion in Nonlinear Layered Structures

S. P. Kulik, A. V. Burlakov, Maria V. Chekhova +2 more

Vlasta Peřinová, A. Lukš, J. Křepelka +1 more

Jan Peřina, A. Lukš, Ondřej Haderka +1 more

Surface spontaneous parametric down-conversion is predicted as a consequence of continuity requirements for electric- and magnetic-field amplitudes at a discontinuity of chi;{(2)} nonlinearity. A generalization of the usual two-photon spectral amplitude is suggested to describe this effect. Examples of nonlinear layered structures and periodically poled nonlinear crystals show that surface contributions to spontaneous down-conversion can be important.

Dalibor Javůrek, Jan Peřina

A rigorous description of volume and surface spontaneous parametric down-conversion in one-dimensional nonlinear layered structures is developed considering exact continuity relations for the fields' amplitudes at the boundaries. The nonlinear process is described by the quantum momentum operator that provides the Heisenberg equations whose solution is continuous at the boundaries. The transfer-matrix formalism is applied. The volume and surface contributions are clearly identified. Numerical analysis of a structure composed of 20 alternating GaN/AlN layers is given as an example.

Cameron Okoth, Andrea Cavanna, Tomás Santiago‐Cruz +1 more

Jan Peřina, A. Lukš, Ondřej Haderka

In order to fulfill the continuity requirements for electric- and magnetic-field amplitudes at discontinuities of ${\ensuremath{\chi}}^{(2)}$ nonlinearity, additional photon pairs have to be emitted in the area of discontinuity. Generalized two-photon spectral amplitudes can be used to describe properties of photon pairs generated in this process that we call surface spontaneous parametric down-conversion. The spectral structure of such photon pairs is similar to that derived for photon pairs generated in the volume. Surface and volume contributions to spontaneous down-conversion can be comparable as an example of nonlinear layered structures shows.