A NOVEL LOW-LOSS IN-LINE BIMODAL-FIBER TAP - WAVELENGTH-SELECTIVE PROPERTIES

A novel inline fiber tap is fabricated from bimodal fiber. The tap is a combination of two elementary devices: a low-loss (resonant) mode converter and a special fused-taper coupler. Efficient coupling of light for a narrow wavelength band (<10 nm) is demonstrated. The center-wavelength of the band can be selected by tuning the resonant condition for intermodal coupling in the mode converter. The uncoupled (nonresonant) light passes through the tap, exhibiting low excess loss (<0.2 dB). The tap has application in linearly tapped fiber optic distribution systems. © 1990 IEEE