Solution doping method of making an optical amplifying fiber

• Main Authors: TAKEDA KEIKO, OKAMURA KOJI
• Format: Patent
• Language: English
• Published: 25.06.2002
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; DEVICES USING STIMULATED EMISSION; ELECTRICITY; GLASS; JOINING GLASS TO GLASS OR OTHER MATERIALS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS

An optical amplifying fiber including a clad, a first core provided inside the clad and containing Ge, a second core provided inside the first core and containing Er and Al, and a third core provided inside the second core and containing Ge. The second core has a refractive index higher than that of the clad, and the first and third cores have refractive indexes each of which is higher than that of the second core. Since the third core having the high refractive index is provided at a central portion, it is possible to make smaller a mode field diameter and hence to improve a conversion efficiency of pumping light into signal light. Further, since the second core contains Al as an amplification band width increasing element, it is possible to sufficiently ensure a wide amplification band width.