Design and characterization of a plastic optical fiber active coupler

In this letter, we report on the first active coupler developed with the plastic optical fiber technology. The device constructed combines the characteristics of the most important devices arising from this technology, which are switches and couplers. The solution adopted is based on the structure of a passive contact coupler and on the switching properties of a nonquiral nematic liquid crystal. The device designed yields an experimental coupling of 4.5 dB with excess losses under 2.5 dB if the device acts as a coupler; and a dynamic range of 3 dB and switching times of 2 ms if the device acts as a switch.