PURPOSE: To provide an optical functional glass and a fiber amplifier, etc., using the same for optically amplifying in a 1.3μm wavelength band.
CONSTITUTION: At least one type of Sm and Dy is added as second rare earth element together with Pr of a first rare earth element to optical functional glass to be used for an optical fiber 30. The second rare earth element is excited due to presence of an exciting light having 1.07, 0.98μm, etc., wavelengths from a laser light source 32. The first rare earth element which receives energy from the second rare earth element is also excited in response to it. The excited first rare earth element is guided to a signal light to generate an emitting light having 1.3μm a wavelength band corresponding to a transition 1D2→ 1G4. If the exciting light exceeds a predetermined intensity, the signal light is amplified.
KOGO TAKASHI
NAKAZATO KOJI
KANAMORI HIROO
WATANABE MINORU
MIYAJIMA YOSHIAKI
NIPPON TELEGRAPH & TELEPHONE