Abstract: Disclosed is a microbend fiber optic coupler and a method of forming same. The microbend fiber optic coupler includes two pairs of pigtail ends oriented one beside the other and having a bent fused biconically tapered coupling region interposed therebetween.

Abstract: Disclosed is a microbend fiber optic coupler and a method of forming same. The microbend fiber optic coupler includes two pairs of pigtail ends oriented one beside the other and having a bent fused biconically tapered coupling region interposed therebetween.

Abstract: Disclosed is a microbend fiber optic coupler and a method of forming same. The microbend fiber optic coupler includes two pairs of pigtail ends oriented one beside the other and having a bent fused biconically tapered coupling region interposed therebetween.

Abstract: Disclosed is a fiber optic coupler which includes a fused, stretched, and twisted biconical tapered region; a first pair of fiber pigtail ends extending from a first end of said biconical tapered region; a second pair of fiber pigtail ends extending from a second end of said biconical tapered region; and polarization dependent loss preclusion means disposed within said biconical tapered region. Further disclosed is a method for forming the polarization insensitive coupler as described.

Abstract: A structure and method are provided to compensate for temperature changes on wavelength shifting in DWDM by reducing tension in a fused-fiber DWDM when temperature increases and increasing tension when temperature decreases, thereby stabilizing wavelength shifts throughout the range of operating temperatures. The DWDM, which is enclosed by a protective package in some embodiments, is connected to substrates of different thermal expansion coefficients, such that the fused-fiber portion of the DWDM exhibits negative thermal expansion, i.e. contracts when temperature increases and expands when temperature decreases. As a result, temperature-induced wavelength shifts are minimized due to a passive thermal compensation, which can be easily adjusted. In other embodiments, twisting the fused-fiber portion of the DWDM to obtain optimum phase matching minimizes the polarization-dependent losses in the incoming light.

Abstract: A structure and method are provided to improve stability and performance of multiplexers in dense WDM applications. A wavelength division multiplexer (WDM) utilizing an unbalanced Mach-Zehnder Interferometer has first and second fused-fiber couplers cascaded together by two optical connecting fibers having different optical path lengths. The different path lengths can be attained with connecting fibers of two different lengths or two different refractive indexes. In some embodiments, a portion of a fiber with a different refractive index than either or both connecting fibers is fuse-spliced between a connecting fiber to provide the path length difference. Tension can be applied to the fused-fiber multi-window WDM to obtain the desired passband prior to mounting the WDM within a supporting substrate for protection. A passive thermal compensation technique can be used to minimize the thermal effect on the passband wavelengths for dense WDM applications.