Experimental studies on wavelength division bidirectional optical amplifiers using an Er/sup 3+/-doped fiber

This paper presents a novel structure of an Er/sup 3+/-doped fiber amplifier capable of bidirectional operation through the wavelength division multiplex method. The idea is to combine an Er/sup 3+/-doped fiber, pump devices, optical isolators, and wavelength selective couplers so that two lightwaves having different wavelengths pass each proper isolator. The suitable structure was determined from experimental studies on several basic amplifier configurations. Optical gains of more than 25 dB were attained in both wavelength regions of 1.533 /spl mu/m and 1.55 /spl mu/m. Successful bidirectional operation of the amplifier was confirmed by means of a 2.488-Gbit/s-signal transmission experiment.<
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