Fiber-Chip-Fiber Mode/Polarization/Wavelength Transmission and Processing with Few-Mode Fiber, (de)Multiplexing SiO₂ Chip and ROADM Si Chip

The emergence of optical communications has opened up new perspectives for high-capacity data transmission and signal processing, to meet the demand of the increasing data traffic. Despite significant progress in multi-dimensional multiplexing for capacity scaling in fiber-optic communications or photonic networks-on-chip, achieving high-capacity data transmission and signal processing in an entire fiber-chip-fiber system remains a great challenge. This challenge is attributed to the lack of effective multi-dimensional coupling between fiber and chip. Here, the 3D (de)multiplexing SiO2 chip inscribed by femtosecond laser direct writing is proposed to achieve the multi-dimensional coupling between the few-mode fiber (FMF) transmission link and the silicon processing network. Combined with the 2D silicon chip fabricated by a standard lithography process, a multi-dimensional fiber-chip-fiber communication system designed to transmit and process the hybrid wavelength-, mode- and polarization-division multiplexing signals in FMF is constructed. The silicon chip integrates Mach-Zehnder interferometer (MZI) switches and arrayed-waveguide gratings (AWGs) to serve as a reconfigurable optical add/drop multiplexer (ROADM). As a proof-of-concept demonstration, a 96-channel FMF-chip-FMF communication system with a data transmission capacity of 4.032 Tbit s(-1), achieving a bit-error ratio (BER) of less than 3.8 x 10(-3), is successfully implemented.