The silicon nitride planar waveguide platform has enabled a broad class of low-loss planar-integrated devices and chip-scale solutions that benefit from transparency over a wide wavelength range and fabrication using wafer-scale processes. As a complimentary platform to silicon-on-insulator and III-V photonics, Si 3 N 4 waveguide technology opens up a new generation of system-on-chip applications not achievable with the other platforms alone. The availability of low-loss waveguides (<;1 dB/m) that can handle high optical power can be engineered for linear and nonlinear optical functions, and that support a variety of passive and active building blocks opens new avenues for system-on-chip implementations. As signal bandwidth and data rates continue to increase, the optical circuit functions and complexity made possible with Si 3 N 4 have expanded the practical application of optical signal processing functions that can reduce energy consumption, size, and cost over today's digital electronic solutions. Researchers have pushed the performance of photonic-integrated components beyond other integrated platforms, including ultrahigh Q resonators, optical filters, highly coherent lasers, optical signal processing circuits, nonlinear optical devices, frequency comb generators, and biophotonic system-on-chip. This review paper covers the history of low-loss Si 3 N 4 waveguide technology, a survey of worldwide research in various devices and applications, and the status of Si 3 N 4 foundries. Heat-resistant silicon nitride is used in aluminum casting technology for melting channels riser and protective tubes (e.g., for immersion heating elements, pyrometers, etc.). An increase in tool life of up to 20 times longer than conventional steel components can be expected. This also applies to risers made of Si₃N₄ for die casting of, for example, aluminum rims. This makes it possible to meet remarkable quality and surface finish requirements. Electromagnetic pumps play an increasingly important role in the search for developing faster and more energy-efficient processes for melting aluminum. These pumps enable the molten bath to be mixed quickly and evenly without mechanically moving parts. If you are looking for high quality, high purity and cost-effective Silicon Nitride, or if you require the latest price of Silicon Nitride, please feel free to email contact mis-asia.