a switch for selectively coupling light from two input fibers to a selected two of plurality of output optical fibers . the switch was designed to handle standard fiber optical connectors which have been polished and meet the specifications for the optical performance . the duplex mechanical switch creates a method to physically switch two fibers to another two fibers . the performance regarding insertion losses , back reflection , crosstalk , immunity against backscattering of light and insensitivity to the wavelength of the light is consistent with this mechanical switch .