OPTICAL FIBER FOR AMPLIFICATION

摘要

PURPOSE:To provide an optical fiber for amplification having high gain and excellent noise property by efficiently removing a natural emitting beam generated in the optical fiber for amplification without installing a band-pass-filter or the like. CONSTITUTION:In the optical fiber composed of a core added with Pr or Er and a clad, the optical fiber for amplification is made by adding an absorbing body for absorbing the natural emitting beam from Pr or Er to the clad. An inexpensive and highly reliable optical communication system is structured by constituting a preamplifier using the optical fiber for amplification to apply it to optical communication. The wave length to be amplified is not fixed by the characteristic of the band-pass-filter and the large degree of freedom is attained since it is not necessary to provide the band-pass-filter or the like for eliminating the natural emitting beam.