In high-speed optical communication modules, Block is used for wavelength splitting and combining of CWDM. The CWDMBLOCK is made by bonding the high reflectivity prism and CWDM filters, and thelight beam is divided or combined through multiple reflections inside theprism. The BLOCK used for the transmitting end is the MUX component, and theBLOCK used for the receiving end is the DEMUX component.