Silicon Nitride Integrated Photonics from Visible to Mid-Infrared Spectra

Silicon nitride (Si3N4) photonic integrated circuits (PICs) are of great interest due to their extremely low propagation loss and higher integration capabilities. The number of applications based on the silicon nitride integrated photonics platform continues to grow, including the Internet of Things (IoT), artificial intelligence (AI), light detection and ranging (LiDAR), hybrid neuromorphic and quantum computing. It's potential for CMOS compatibility, as well as advances in heterogeneous integration with silicon-on-insulator, indium phosphate, and lithium niobate on insulator platforms, are leading to an advanced hybrid large-scale PICs. Here, they review key trends in Si3N4 photonic integrated circuit technology and fill an information gap in the field of state-of-the-art devices operating from the visible to the mid-infrared spectrum. A comprehensive overview of its microfabrication process details (deposition, lithography, etching, etc.) is introduced. Finally, the limitations and challenges of silicon nitride photonics performance are pointed out in an ultra-wideband, providing routes and prospects for its future scaling and optimization. This manuscript reviews recent advances in the fabrication processes and applications of silicon nitride photonic integrated circuits in the broadband spectrum from visible to mid-infrared wavelengths. The details of material deposition, lithography, etching, and fabrication of coupling structures are analyzed. An in-depth analysis of relevant publications by key groups over more than 10 years is presented along with the latest achievements in creating state-of-the-art devices based on Si3N4 integrated photonics. image