Development of miniature optical fiber hybrid WDM coupler employing the FBT technology

An innovative technique for fabricating the optical fiber hybrid wavelength-division multiplexing (WDM) coupler is presented. The device is comprised of two components, a wavelength division multiplexer and an optical fiber coupler, in a miniature stainless steel tube. The outstanding features of the ultra-low polarization dependent loss (PDL) under 0.05 dB and the compact size of ∅3.5 × 65 mm for bare-fiber type of package are accomplished by using the pioneering methodology combining the main techniques of twisted and parallel fusion processes in the fused biconical taper (FBT) technology. Besides, its miniaturization is more competitive in both of the applications of optical communication and sensing systems where a compact-sized package is required for extending the flexibility of installation.

► We develop an innovative two-step fusion process to accomplish a miniature hybrid optical fiber WDM coupler.
► The hybrid device we developed is superior in having multi-functions with a miniature package.
► PDL of the hybrid device is less than 0.05 dB which is much lower than the specification for the industrial application.
► By passing the tests of Telcordia GR1209 and GR1221, it ensures excellent product reliability under adverse environments.