Efficient Broadband Wavelength Conversion in AlGaAsOI Nonlinear Nanowaveguides Using Low-Power Continuous-Wave Pump

Nonlinear wavelength conversion based on four-wave mixing (FWM) is a key function for optical signal processing in photonic integrated systems. Although various integrated waveguide platforms have been proposed for on-chip wavelength converters, it remains a great challenge to realize efficient broadband wavelength conversion using a low-power pump due to the lack of sufficient nonlinear gain in waveguides. To address this challenge, we develop centimeter-scale long, low-loss, spiral nanowaveguides on a highly nonlinear AlGaAs-on-insulator (AlGaAsOI) platform. Through dedicated waveguide dispersion engineering, we demonstrate a broadband wavelength conversion with a 3-dB bandwidth over 130 nm at the telecom bands and a flat conversion efficiency over −10 dB in the whole band, using a single continuous-wave low-power pump of ∼18 dBm. A theoretical analysis not only shows excellent agreement with our experimental results but also reveals a viable route for further performance improvement by reducing the propagation loss and/or tailoring the dimension of waveguides. The demonstrated high-performance wavelength converters provide a practical solution for compact and power-efficient wavelength conversion in optical signal processing. Furthermore, our work highlights the great potential of highly nonlinear AlGaAsOI nanowaveguides in chip-scale χ⁽³⁾-based nonlinear applications with ultrahigh performance.