Ultra-Efficient and Broadband Nonlinear AlGaAs-on-Insulator Chip for Low-Power Optical Signal Processing

Four-wave mixing (FWM) is a versatile optical nonlinear parametric process that enables a plethora of signal processing functionalities in optical communication. Realization of efficient and broadband all-optical signal processing with ultra-low energy consumption has been elusive for decades. Although tremendous efforts have been put into developing various material platforms, it has remained a challenge to obtain both high efficiency and broadband operation. Here, an aluminum gallium arsenide nonlinear chip with high FWM conversion efficiency per length per pump power and an ultra-broad bandwidth is presented. Combining an ultra-high material nonlinearity and strong effective nonlinear enhancement from a high-index-contrast waveguide layout, an ultra-high conversion efficiency of -4 dB is obtained in a 3-mm-long nano-waveguide. Taking advantage of high-order dispersion, a scheme is presented to realize an ultra-broad continuous conversion bandwidth covering 1280-2020 nm. A microresonator is also utilized to demonstrate a conversion efficiency enhancement gain of more than 50 dB with respect to a waveguide device, which significantly reduces the power consumption. Moreover, wavelength conversion of an optical serial data signal is performed at a bit rate beyond terabit-per-second, showing the capabilities of this III-V semiconductor material for broadband optical signal processing.