| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical fiber amplifier, to which two or more rare earth elements are doped, for controlling amplification of naturally released light from a second rare earth element having the wavelength different from that of the signal light. SOLUTION: In the optical fiber based on the photonic band gap as the principle of waveguide in which a periodical structure of refractive indices is formed in the circumference of a core to which two or more kinds of rare earth elements are doped, the rare earth doped photonic band gap fiber is characterized in having the propagation characteristic that the light in the wavelength of the signal light as the induction release light from a first rare earth element is propagated by the photonic band gap, and, on the other hand, the light in the wavelength of the natural release light from a second rare earth element is not propagated by the photonic band gap but is released or amplification of the natural release light from the second rare earth element is controlled because propagation loss is larger than amplification factor. COPYRIGHT: (C)2008,JPO&INPIT |
