Silicon photonics has developed into a mainstream technology driven by advances in optical communications. The current generation has led to a proliferation of integrated photonic devices from thousands to millions-mainly in the form of c. Silicon photonics has developed into a mainstream technology driven by advances in optical communications. The current generation has led to a proliferation of integrated photonic devices from thousands to millions-mainly in the form of communication transceivers for data centers. Products in many exciting applications, such as sensing and computin. Figure 1 maps the evolution of silicon photonics1,2. Silicon-based photonic integrated circuits (PICs) were introduced in 19853 and low-loss waveguides in a thick silicon on insulator (SOI) process demonstrated in 1991–924,5. Various optical devices were next demonstrated6, and soon, silicon photonics was in the small-scale integration (SSI) era—with 1-to-10 components on a PIC. They included demonstrations of high-speed pn junction modulators7,8,9 and photodetectors (PDs)10,11,12,13, as well as heterogeneous integration of a III-V laser to a silicon PIC14. The next era ushered in the commercial success of silicon photonics. With 10-to-500 components on a PIC, this medium-scale integration (MSI) era saw successful demonstration and adoption of Mach-Zehnder modulator (MZM) in intensity-mo. Through the generations of CMOS process development, many materials were added to silicon to reduce the Power, improve the Performance, and shrink the Area—often called the PPA metrics. The additions include Al and Cu for metal traces, Ge for inducing strain and enabling heterojunction BJTs, and silicon nitride (SiN) for passivation and diffusion barriers. The CMOS R&D budgets and commercial markets are orders of magnitude larger than for silicon photonics, so it is natural for silicon photonics foundries to learn from and adopt the innovations from CMOS processes. Hence, we have seen a similar trend in silicon photonics process development. Besides p/n dopants for high-speed modulation, two materials that are now natively supported by several foundries are (1) Ge high-speed photodet. Photonics & electronics interplaySilicon PICs almost always exist in conjunction with electronic ICs (EICs). When we look at systems based on photonic chips, the landscape today is almost 100% dominated by data communication, and we expect this to continue for the near future. In this context, EICs serve two purposes (Fig. 2): (1) Enable E/O and O/E conversions of the end-to-end data. (2) Bias, control and compensate for temperature and fabrication variations. Thus, photonics serve electronics by providing the data links, and electronics serve photonics by providing control and readout and digital signal processing (DSP). A major difference between photonics and electronics is that photons don't interact and thus are excell. In this section, we describe the top technical impediments to the success of various silicon photonics applications (Table 5), connecting them to some of the challenges and opportunities discussed in previous sections. We limit the impediments to PIC/EIC technology only, excluding economic, regulatory, market, and other factors such as chemistry, biomarkers, quantum advantage, etc. We also do not delve into the benefits of silicon photonics for these applications since most of the previous works describe them in detail.Full size tableFor IMDD transceivers (XVRs) to further improve their energy efficiency (pJ/b) and scale to higher data rates, the modulator.
