Amplification of polarized signals using a helically wound erbium doped fiber amplifier

摘要

The relative insensitivity of erbium doped fiber amplifiers to the state of polarization of the input signal is considered as an advantage when these devices are used within communication networks. On the other hand, in order to use them in combination with interferometric optical fiber sensors, they should be able to maintain the input polarization state. In this work we present the results obtained for the performance characterization of an EDFA built with a helically wound monomode erbium fiber. The use of a regular winding allows the control of the evolution of the state of polarization of the optical signal to be amplified. We include results of the geometrical and birefringence characterization of two helices built with two different commercial erbium fibers, The amplification of polarized signals has been evaluated for the C band (1530nm-1560nm). It presents a high gain for small as well as for saturated signals. In regard with the noise due to the amplified spontaneous emission, it was evaluated also for small as well as for saturated signals. The values we measured are below the theoretical predictions based on typical EDFAs built with an irregularly wound erbium fiber.