Integrated optical signal processing with silicon platform

Silicon photonics offers a promising integration platform facilitating chip-scale optical signal processing. We review recent research progress in integrated optical signal processing with silicon platform by employing advanced multi-level modulation formats. Using fabricated silicon waveguides, gratings, couplers, microring resonators, vertical slot waveguides and hybrid plasmonic waveguides, we demonstrate chip-scale signaling for terabit optical interconnects, chip-scale wavelength/polarization/mode (de)multiplexing, chip-scale unidirectional wavelength conversion and bidirectional data exchange, chip-scale high-base optical computing (addition, subtraction, hybrid), chip-scale optical coding/decoding, and chip-scale optical signal regeneration. The experimental results indicate favorable performance of integrated optical signal processing on a silicon platform. The exponential growth of global internet traffic has fueled the increasing demand for using advanced modulation formats and robust multiplexing techniques not only in optical transmission links but also in optical signal processing functions. Recently, lots of advanced multilevel modulation formats and various multiplexing techniques, i.e., m-ary phase-shift keying (mPSK), m-ary quadrature amplitude modulation (m-QAM), orthogonal frequency-division multiplexing (OFDM), wavelength-division multiplexing (WDM), and polarization-division multiplexing (PDM), have been widely employed to promote transmission capacity and processing throughput. Meanwhile, recent advances in the density and complexity of photonic integrated circuits (PICs) have facilitated possible integration of complete optical communication systems on a monolithic chip. Silicon photonics is considered to be a promising low cost integration platform enabling chip-scale optical interconnects and optical signal processing owing to its distinct advantages of high index contrast, relaxed latencies, lower power consumption, and compatibility with complementary metal-oxide-semiconductor (CMOS) technology. In this scenario, a laudable goal would be to explore integrated optical signal processing using silicon photonic devices. In this paper, we review our recent research progress in integrated optical signal processing with silicon platform, including: 1) chip-scale signaling for terabit optical interconnects; 2) chip-scale wavelength/polarization/mode (de)multiplexing; 3) chip-scale unidirectional wavelength conversion and bidirectional data exchange; 4) chip-scale high-base optical computing (addition, subtraction, hybrid); 5) chip-scale optical coding/decoding; 6) chip-scale optical signal regeneration.