| 摘要 |
PROBLEM TO BE SOLVED: To allow a small-sized optical amplifier to have a high gain by forming a groove within an optical waveguide provided on a substrate and filling the groove with an Ercontaining solution containing an Er compound. SOLUTION: A substrate 11 is provided with an optical waveguide 12, and a groove 13 is formed along the length of the waveguide 12. The groove 13 is sealed with an Er-containing solution 14. The solution 14 contains an index matching solution or an electrolytic solution as a solvent and an Er compound as a solute, and has a refractive index equivalent to that of the waveguide 12. In such an optical amplifier 10, the solution 14 can contain the Er compound as much as to the solubility of the solvent. Therefore, to obtain a gain of 20 dB which is required for a WDM optical system to transmit light through the solution having a high Er concentration, the length of the solutionsealed groove 13 can be only as short as about several centimeters in the amplifier 10. Hence, according to such an optical amplifier, a high gain can be obtained with a small size. |
