LOW-COHERENCE REFLECTOMETRY THROUGH SCATTERING MEDIA WITH DEGENERATE 4-WAVE-MIXING IN A THIN NONLINEAR-OPTICAL LAYER

We have demonstrated the coherence filtering operation for optical low -coherence reflectometry via degenerate four-wave mixing (DFWM) in a t hin nonlinear optical layer. To perform proof-of-principle DFWM experi ments, we use a thin dye solution with a thermally-induced optical non linearity. In contrast to previous works, which used c.w. light-emitti ng diodes or Fourier-transform limited ultra-short laser pulses, we ha ve used broad-band nanosecond laser pulses for depth resolved measurem ents through scattering media.