Coarse Wavelength Division Multiplexing (CWDM) is a type of optical wavelength management device that are based on proven ultra low-loss thin-film filter (TFF) technology. It features small size, high reliability, high extensibility, simultaneous transmission of multi-wavelength. CWDM has gained prevalence in multi-wavelength digital transport architectures because it enables the use of very low cost uncooled distributed feedback (DFB) laser transmitters. Moreover, their powering requirements are reduced and reliability is increased. Raycore provides whole series of 1xN CWDM products that are tailored for specific applications. All products meet GR-1209-CORE, GR-1221-CORE and ITU-T G.694.2 requirements.