UC Davis

Optical communication systems are being widely deployed all around the world. One ofthe key techniques behind all these properties is wavelength division multiplexing/demultiplexing (WDM) [1]. To implement WDM systems in photonic integrated circuits, arrayed waveguide grating (AWG) plays an important role as the core device doing both the demultiplexing and routing functions of wavelength channels [2]. The working principles of AWG are discussed in detail in Chapter 2. Based on these properties, the workflow of determining all the geometric parameters needed for designing a low-loss functional AWG is presented in the second section in Chapter 2. To have an accurate estimation of the performance of the AWG being designed, the last section in Chapter 2 presents the flowchart showing how to build a fast and accurate AWG simulator using Gaussian approximation, Fourier Transform, and mode coupling theory. Apart from basic theories of AWG design, examples including traditional AWG router (AWGR) and some other fancy photonic integrated devices such as flat-top AWG, reflective AWG/AWGR, polarization-insensitive AWG are discussed in depth in Chapter 3. In Chapter 4, fabrication processes of SiN-based waveguide platform and measurement results of regular AWGs and reflective AWGs are described in detail. In Chapter 5, sophisticated system-level applications using AWGs including optical arbitrary waveform generator (OAWG), optical synaptic interconnections, and a passive part of WDM laser are introduced.