Second harmonic generation using d₃₃ in periodically poled lithium niobate microdisk resonators

A fabrication process allowing for the production of periodically poled lithium niobate (PPLN) photonic devices with any domain pattern and unit size down to 200 nm is developed by combining semiconductor fabrication techniques and piezo-force-microscopy tips polarization. Based on this fabrication process, PPLN microdisk resonators with quality factors of 8×104 were fabricated from a Z-cut lithium niobate film. Second-harmonic generation (SHG) utilizing d33 in the whole cavity was demonstrated in a PPLN microdisk with a 2 μm-spatial-period radial domain pattern. The SHG conversion efficiency was measured to be 1.44×10−5  mW−1. This work paves the way to fabricate complex PPLN photonic devices and to obtain efficient nonlinear optical effects that have wide applications in both classical and quantum optics.