Four-wave mixing in one-dimensional photonic crystals: inhomogeneous-wave excitation

We present what is to our knowledge the first study of nonlinear four-wave mixing in one-dimensional photonic crystals. The possibility of inhomogeneous-wave excitation at the four-wave mixing frequency ω3=2ω1-ω2 for two noncollinear beams of femtosecond laser pulses is demonstrated. As a result of this effect the wave at the frequency of four-wave mixing may be guided along the surface of the photonic crystal. Experiments of this type open the possibility of development of a new tool based on photonic crystal devices for coherent Raman spectroscopy of surfaces and of nanometer and submicrometer scale layers.