Integrated Silicon Photonic Components for Advanced Optical Communications

Optical communications have been the main motivation for silicon photonics since late 1980s. Both industry and research community have witnessed a great progress in silicon photonics with a plethora of device demonstrations. In the meantime, optical communications have also advanced towards a new paradigm which enables much more opportunities in silicon photonic device engineering and applications. Currently, the compatibility of silicon photonic devices and circuits for practical advanced optical communication systems remains an open research topic. In this thesis, we study the applications of different silicon components for several advanced communication systems.;In the near future, the conventional lightwave communication system will not be able to meet the exponentially increasing demand for transmission capacity. Much effort has been made towards spectrally efficient long haul transmission techniques such as optical orthogonal frequency division multiplexing (OFDM) and Nyquist wavelength division multiplexing (WDM). Silicon modulator has been demonstrated within the last decade, but the compatibility of silicon modulator in such advanced system needs to be investigated. Silicon modulator is studied in an optical OFDM system and the advanced modulation formats are successfully generated. On the other hand, silicon coupled resonator optical waveguides (CROW) is proposed for generating Nyquist WDM signal and the performance is studied.;For optically routed network, optical performance monitoring (OPM) has been proposed for physical layer fault detection which is important for ensuring the quality of service. Low-cost and integrated optical performance monitor is desired for system-wide implementation. Based on the mature silicon photonic platform, optical signal to noise ratio (OSNR) monitoring is studied in this thesis using several integrated devices. Chromatic dispersion monitoring is also experimentally demonstrated.;Elastic optical networking was proposed recently for efficient bandwidth allocation in the space and time domain. This requires the transceiver interface with enhanced flexibility in the physical layer. Conventional Mach-Zehnder interferometer (MZI) based receiver is not able to handle a wide range of bit rate for phase modulated signal. Here silicon microring based receiver is designed and demonstrated for variable bit rate operation in phase coded system. Differential (quadrature) phase shift keying signal is successfully demodulated by wavelength tunable silicon microring resonator. The flexible bit rate receiver is achieved by integration of a ring demodulator and a Ge photodetector.;Passive optical network (PON) is considered as a primary solution for the "last mile" problem in access network. In 2012, time wavelength division multiplexing (TWDM) PON has been chosen to be the solution for the next generation PON stage-2 (NG-PON2). We propose using cascaded silicon ring as a downstream receiver which is scalable for higher data rate and the device can be potentially fabricated with low cost. Besides, silicon photonics can also play an important role in ultra-wideband (UWB) impulse radio system. A colorless UWB monocycle pulse generation is achieved on silicon chip and is suitable for distribution over optical fiber.