| 摘要 |
PROBLEM TO BE SOLVED: To realize a thorium ion-containing amplifier or a thorium ion-containing ASE light source whose amplification band width or emission wavelength band is 1360 to 1460 nm (E band) by the use of an amplifying medium loaded with thorium ion. SOLUTION: An amplifying fiber 103 is composed of a core loaded with thorium ion and cladding loaded with erbium ion. When signal light or ASE having a wavelength of 1460 nm or below is guided by a distance of 1 mm through the amplifying fiber 103, amplified spontaneous emission having a wavelength band of 1460 to 1520 nm is generated by the amplifying medium. A thorium loading concentration Conc (Tm), an erbium loading concentration Conc (Er), and an overlapping ratioΓof a core to a mode field of signal light are set to satisfy formula, Conc (Er)/Conc (Tm)×(1-Γ)≥0.66, so as to absorb 60% or above of the amplified spontaneous emission originating from the amplifying medium. When the left member of the formula is 0.66 to 1.0E+5, a gain of 10 dB or above can be obtained. COPYRIGHT: (C)2005,JPO&NCIPI |
