LAUSR

Second-order non-linear susceptibility ( χ 2 ) is the cause of many non-linear processes in optics including second harmonic generation, sum frequency generation and difference frequency generation. Optical frequency combs based on χ 2 , i.e. quadratic frequency combs, hold the promise of reducing the devices power consumption and footprint since χ 2 materials present a stronger non-linearity than χ 3 materials, which suggests that higher efficiencies can be achieved. In this work, we will revisit the latest quadratic combs experimental advances, concerning power threshold, span and wavelength conversion efficiency.