Second harmonic generation in LiNbO3 and LiTaO3 in the millimeter wave region

Abstract
Second harmonic radiation at 70 GHz was generated using a 35‐GHz magnetron in bulk ferroelectric LiNbO3 and LiTaO3 located in a rectangular waveguide. The measured second harmonic output was comparable to theoretical predictions with peak powers as high as 9.8 W for LiTaO3 and 7.6 W for LiNbO3 for an input power of 24 kW. The output power varied periodically as a function of the sample length due to cavity resonance effects.