ETERN's 100GHz and 50GHz DWDM TFF is the core chip in dense wavelength division multiplexing DWDM transmission network, widely used in OTN backbone, metro and 5G pre-transmission network, next-generation 50G-PON, the first independent core technology in China, invested heavily in multiple coating machines and auxiliary production and testing equipment, and adopts the advanced ion-assisted deposition IAD technology to achieve Ultra-smooth polishing, and very small wavelength temperature drift, reaching the international first-class level.