Abstract: A narrowband twisted optical fiber wavelength division multiplexer ("WDM") and a method for fabricating the WDM. The WDM includes a twisted pair of first and second optical fibers that are fused together, each of the first and second fibers having a first and second end. In the WDM, when a first and second light are applied to the first end of the first fiber, they will appear on the second end of the first fiber and the second end of the second fiber, respectively. When the first light enters the second end of the first fiber, and the second light is applied to the second end of the second fiber, they will both appear on the first end of the first fiber.

Abstract: A terminator for use with an optical fiber access port structure that supports an optical fiber having an optical end face exposed to communicate with a like end face of another fiber, the terminator comprising a pig-tail-free compact supporting body carrying within itself light-absorbing means and shaped to removably interfit with the access port structure to present the light-absorbing means in light transferring relationship to the exposed end of said optical fiber at the port in manner to absorb incident light from the fiber end face and prevent back-reflection.