| 摘要 |
PROBLEM TO BE SOLVED: To compensate for the temperature dependency of EDFA in wavelengths region of 1,530 nm-1,535 nm and to perform the wavelength multiplex transmission of the wavelengths 1,530 nm-1,610 nm. SOLUTION: A long-cycle grating, for which grating cycle change is about 300-500μm, is formed in an optical fiber, and the optical fiber is provided with light transmission loss characteristics, having light transmission loss peak in the range of about 1,500-1,525 nm due to a propagation mode via the long-cycle grating of the optical fiber and the clad mode of a higher order. The temperature-dependent shift amount of a light transmission loss peak wavelength is set to about 0.02/ deg.C to about 0.05/ deg.C, light transmission loss (characteristic line (a)) at 65 deg.C in the wavelength 1,530 nm is made larger by about 0.4 to 0.6 dB than the light transmission loss (characteristic line b) at 25 deg.C by the shift and gain temperature dependency in a device, for which the EDFA and an etalon filter are combined, is compensated to be±0.2 dB or less. |
