Domain inversion in KTiOPO4 using electron beam scanning

Abstract
Domain inversion in c‐cut KTiOPO4 was produced by scanning an electron beam on the −c face. The domain reversal occurred through the 1 mm thickness of the sample. Second‐harmonic conversion efficiency of 7×10−5 was measured for a fifth‐order grating by focusing the beam to a 7 μm spot in a 500‐μm‐long domain‐inverted KTP crystal. This efficiency is close to the theoretical value of 9×10−5. The measured phase matching bandwidth was 1.9 nm, which is in agreement with the theoretical value of 1.5 nm indicating that the domain‐inverted grating is reasonably uniform over its entire length.