Eliminación de ruido de ASE en una fibra dopada con erbio empleando un filtro basado en el interferómetro de Sagnac con fibra de Hi-Bi en el lazo

Abstract

We experimentally investigate the application of a thermically tunable filter based on a Sagnac interferometer with high birefringence (Hi-Bi) fiber in the loop to eliminate the biggest contribution in the amplified spontaneous emission (ASE) noise in an Erbium-doped fiber (EDF). The Sagnac interferometer provides a periodic transmitance that depends on the wavelength, which is used as a bandpass filter if it is selected the length of the Hi-Bi fiber appropriately in the loop. Furthermore due to its high sensibility to temperature variations, it is possible to adjust the transmitance of the interferometer and to use it like thermically tunable filter. The experimental results show that it is possible to eliminate the biggest contribution of ASE (peak around 1530 nm) and teherefore this device offers a great potential to be used in Erbium-doped fiber amplifiers (EDFAs) like suppressive of ASE noise.