Silicon-organic hybrid (SOH) modulators add a highly efficient nonlinear organic electro-optic cladding material to the silicon photonic platform, thereby enabling efficient electro-optic modulation. In this book, the application potential of SOH modulators is investigated. Proof-of-principle experiments show that they can be used for high-speed communications at symbol rates up to 100 GBd and operated directly from a field-programmable gate array (FPGA) without additional driver amplifiers.

A short introduction to the theory of surface plasmon polaritons (SPPs) is given. The application of the SPPs in on-chip signal processing is discussed. In particular, two concepts of plasmonic modulators are reported, wherein the SPPs are modulated by 40 Gbit/s electrical signals. Phase and Mach-Zehnder modulators employing the Pockels effect in electro-optic organic materials are discussed. A few micro-meter long SPP absorption modulator based on a thin layer of indium-tin-oxide is reported.

To create photonic multi-chip modules, integrated photonic chips need to be connected internally and to external glass fibers. A novel approach to address this task is the concept of photonic wire bonding, where free-standing polymer waveguides are printed in-situ by two-photon polymerization. This book contains a detailed description of the methodology of photonic wire bonding together with a number of key experiments.

Energy-efficient Tbit/s optical interconnects are key elements for future communication systems. Three novel optical frequency comb sources are investigated, which have the potential of being integrated in chip-scale Tbit/s transmitters. Such frequency combs provide a large number of carriers. The equidistance of the comb lines helps to minimize spectral guard bands. For each type of comb source, coherent data transmission experiments show the potential for Tbit/s data transmission rates.

Among the various elements of the silicon photonics platform, electro-optic IQ modulators play an important role. In this book, silicon-organic hybrid (SOH) integration is used to realize electro-optic IQ modulators for complex signal processing. Leveraging the high nonlinearity of organic materials, SOH IQ modulators provide low energy consumption for high-speed data transmission and frequency shifting. Furthermore, the device design is adapted for commercial foundry processes.