| 摘要 |
PURPOSE:To obtain an optical amplification gain in a 1.65mum wavelength band by providing an optical transfer line formed to have an optical functional glass to be added with Pr<3+> as active substance to propagate a signal light of a predetermined wavelength, and an exciting light source for generating an exciting light having a predetermined wavelength. CONSTITUTION:An exciting light having 1.4mum of wavelength band output from a laser light source 12 is incident to a coupler 13 through an optical fiber 19a, and further incident into an optical fiber 10 through an optical fiber 18b. Since Pr<3+> is added as active substance to the core of the fiber 10, the Pr<3+> excited in a predetermined state becomes capable of emitting a light having 1.65mum of a wavelength band. That is, the Pr<3+> is excited by the exciting light having 1.4mum of a band incident to the fiber, electrons at its bottom level <3>H4 are once excited to a level <3>F4, energy such as phonon, etc., is discharged, and it is then transited to a level <3>F3. When an inverted distribution is formed between the level <3>F3 and the level <3>H4 by such excitation and transition without radiation, lights of three levels having a peak of 1.65mum of wavelength band can be emitted. |
