C-CWDM is a compact Mux/Demux module that achieves both space saving and high performance in CWDM systems. The unique optical design using high-performance dielectric multilayer filters achieves low insertion loss (≦1. 5 dB), high isolation, and low PDL. In a package less than one-fourth the size of conventional CWDM modules, these CCWDMs significantly improve optical performance, while reducing. CCWDM, short for Compact Coarse Wavelength Division Multiplexing, is a wavelength division multiplexing technology based on Thin Film Filters (TFF). In practical terms, CWDM SFP modules are.