Second-order nonlinear optical processes on a CMOS-compatible 8-inch aluminum nitride photonics platform

Aluminum nitride (AlN) is an emerging CMOS-compatible material for integrated photonics and can be deposited at wafer scale using a single-step physical vapor deposition process. Compared with conventional silicon photonics materials, AlN uniquely offers both a strong second-order nonlinear optical response and intrinsic piezoelectric properties, enabling efficient second-order nonlinear optical generation and on-chip tuning functionalities. In this work, we demonstrate significant second-order nonlinear optical processes in an AlN microring resonator fabricated on a CMOS-compatible 8-inch AlN photonics platform. The microring exhibits an intrinsic quality factor exceeding one million. When pumped near 1580 nm, pronounced second-harmonic generation (SHG) around 790 nm is observed using a visible-wavelength spectrum analyzer, with a side-mode suppression ratio exceeding 20 dB. The demonstrated second-order nonlinear optical performance on a wafer-scale, CMOS-compatible AlN photonics platform highlights its strong potential for integrated frequency-comb generation and applications in AR/VR, biosensing, and quantum photonics.