There are many types of WDM(wavelength division multiplexing) technologies known at present, such as FBT (Fused Biconical Taper), FBG (Fiber Bragg Grating), TFF (Thin Film Filter), AWG (Arrayed Waveguide Grating), EDG (Etched Diffraction Grating), MZI (Mach-Zehnder Interferometers), and MRR (Micro Ring Resonator). Among them, TFF and AWG are the two most commonly used WDM technologies. This article will introduce the structure and working principle of TFF WDM devices.
The structure of a three-port WDM device includes a dual-fiber collimator, a single-fiber collimator, and a TFF filter.
Optical Passive Components 