ULTRA HIGH EFFICIENCY FREQUENCY CONVERTER FOR USE IN GUIDED OPTICS

摘要

The invention relates to a frequency converter including a waveguide and a non-linear medium (NLM) wherein the phase tuning condition between the non-linear polarisation and the generated waves is locally satisfied. The invention is characterized in that an additional layer (C) is provided on the medium (NLM), with the refractive index of said layer being such that it increases the conversion efficiency of incident waves into the waves generated within the waveguide. The layer can be a balancing conversion layer with a refractive index close to that of the medium (NLM). The conversion efficiency can be further enhanced by means of an intermediate layer (Cex) provided between layer (C) and the medium (NLM), with a refractive index close to that of the waveguide. The invention is useful in the field of frequency doublers and optical parametric oscillators.