Differences between Filter WDM and FBT WDM

1. Technical Principles:

(1) Filter WDM (Thin - Film Filter Type)

Based on “the wavelength selectivity of the thin - film filter (TFF)”. The filter, through the interference effect of multiple layers of dielectric films, only allows specific wavelengths (target channels) to pass through and reflects other wavelengths. By connecting multiple - stage filters in series, multiplexing / demultiplexing of multiple wavelengths can be achieved.

(2) FBT WDM (Fused- Biconical Tapered Type)

Based on ”the power coupling of fiber fused - biconical tapering”. After twisting two or more optical fibers, they are melted and stretched at high temperatures to make the core regions of the optical fibers couple. By taking advantage of the differences in the transmission constants of optical signals of different wavelengths in the coupling region, multiplexing / demultiplexing of a limited number of wavelengths is achieved (only supporting a few channels).

2. Advantageous Application Scenarios:

(1) Filter WDM: The First Choice for High-Demand Scenarios

① High - bandwidth requirements for multiple channels

② Long - distance transmission

③ Industrial / outdoor environments

④ Weak optical signal transmission

(2) FBT WDM: The Preferred Choice for Low-cost and Simple Scenarios

① Simple two - wavelength transmission

② Short - distance indoor scenarios③ Projects with limited budgets