All-optical diode in a periodically poled lithium niobate waveguide

We have demonstrated a guided-wave all-optical diode based on engineered quasiphase Matching in a LiNbO3 channel waveguide. For input peak powers beyond 1.5 W at 1.55 μm, the device exhibited a spatially nonreciprocal response, leading to optical isolation with contrasts as high as 90% at 3.1 W, in agreement with theoretical predictions.