Filter-based Wavelength Division Multiplexer (FWDM) is a kind of WDM multiplexer based on the Thin Film Filter (TFF) technology. The FWDM combines or separates light at different wavelengths in a wide wavelength range and is extensively used in EDFA, Raman amplifiers, and WDM optical networks. Fiber-Mart provides a series of FWDM multiplexers for FTTx constructions. Our FWDM product line covers different wavelength windows commonly used in optical fiber systems. All the FWDM multiplexers offer low insertion loss, low polarization dependence, high isolation and excellent environmental stability.