Nonlinear optical patterns: classical and quantum effects, perspectives for applications

We introduce the field of transverse nonlinear optics, and discuss some perspectives for applications, namely the use of spatial solitons for parallel information processing, femtojoule switching and logic gates in vertical cavity surface emitting lasers. We illustrate the quantum aspects of nonlinear optical patterns, focusing on quantum images and critical fluctuations in the degenerate optical parametric oscillator below threshold.