Bright localized patterns in singly resonant optical parametric oscillators

Spatially extended systems out of thermodynamic equilibrium may exhibit a plethora of very interesting and rich dynamical behavior generally related with the emergence of different types of patterns [1] . One classical example of systems of this kind are externally driven dispersive nonlinear optical cavities, where light can propagate indefinitely, interacting nonlinearly with the medium. Here, localized pattern (LP) states consisting in localized spots of light can emerge spontaneously due to a double balance between nonlinearity and spatial coupling (e.g., dispersion) on one hand and energy gain and dissipation on the other hand. These states have been found experimentally in different platforms such as Kerr cavities [2] , [3] and recently in Kerr-quadratic cavities [4] .