New Results in InGaPOI: Efficient SHG and Entanglement Sources from Waveguide Devices Published in Optica!
Congrats to the QPL team alongside collaborators at Aarhus, NIST, and EMode Photonix on demonstrating high performance nonlinear and quantum photonic devices in InGaP-on-insulator!
Nonlinear photonic platforms underpin applications ranging from spectroscopy to quantum communication, yet often face trade-offs between efficiency, loss, and scalability. An emerging platform, thin-film InGaP-on-insulator, combines high nonlinearity with wafer-scale fabrication. Here, we demonstrate second-harmonic generation pumped at 1550 nm with a normalized efficiency of 50 / W in a single-pass III–V waveguide and up to 51 mW of generated signal power. Conversely, devices enable high-brightness generation of time-energy entangled photon pairs with a per-bandwidth generation rate of 7.5 GHz / mW / THz. Using InGaP grown via molecular beam epitaxy (MBE), we show losses below 1 dB/cm at 1550 nm and stable phase matching across fabrication runs. An absolute measurement of the nonlinear response yields d14 = 106 pm / V for InGaP grown via both MBE and metalorganic chemical vapor deposition. These results demonstrate the scalability and efficiency of InGaP-on-insulator for entangled photon-pair sources and nonlinear photonic systems such as mid-infrared frequency conversion.
