An optical fiber amplifying system (100, 300), the optical fiber amplifying system providing amplified optical radiation having an active wavelength, the optical fiber amplifying system comprising: one or more first optical pump sources (120, 324), each configured to output radiation of a pump wavelength; a bridge optical fiber (130, 330), having an input end (131, 331) configured to receive the radiation of the pump wavelength output by the one or more first optical pump sources and an output end (132, 332), an active optical fiber (140, 340) having a first end (141, 341) substantially directly coupled to the output end (132, 332) of the bridge optical fiber (130, 330), and a second end (142, 342), the active optical fiber (140, 340) having an active core, a pump cladding surrounding the active core, and one or more outer claddings surrounding the pump cladding, the active optical fiber (140, 340) being configured to amplify radiation of the first active wavelength when pumped with radiation of the pump wavelength, the bridge optical fiber (130,330) comprising: an inner core configured to guide radiation of the active wavelength, the inner core having an inner core active wavelength refractive index profile and an inner core pump wavelength refractive index profile; an annular pump core disposed about the inner core, the annular pump core being configured to guide radiation of the pump wavelength, the annular pump core having an annular pump core active wavelength refractive index profile and an annular pump core pump wavelength refractive index profile; and one or more outer claddings disposed about the annular pump core, the one or more outer claddings having an outer cladding active wavelength refractive index profile and an outer cladding pump wavelength refractive index profile; wherein the annular pump core is configured to substantially confine one or more guided modes at the active wavelength in the inner core, said optical fiber amplifying system being characterized in that less than 30% of the intensity distribution at the pump wavelength at the output end of the bridge optical fiber overlaps the inner core of the active optical fiber. one or more first optical pump sources (120, 324), each configured to output radiation of a pump wavelength; a bridge optical fiber (130, 330), having an input end (131, 331) configured to receive the radiation of the pump wavelength output by the one or more first optical pump sources and an output end (132, 332), an active optical fiber (140, 340) having a first end (141, 341) substantially directly coupled to the output end (132, 332) of the bridge optical fiber (130, 330), and a second end (142, 342), the active optical fiber (140, 340) having an active core, a pump cladding surrounding the active core, and one or more outer claddings surrounding the pump cladding, the active optical fiber (140, 340) being configured to amplify radiation of the first active wavelength when pumped with radiation of the pump wavelength, the bridge optical fiber (130,330) comprising: an inner core configured to guide radiation of the active wavelength, the inner core having an inner core active wavelength refractive index profile and an inner core pump wavelength refractive index profile; an annular pump core disposed about the inner core, the annular pump core being configured to guide radiation of the pump wavelength, the annular pump core having an annular pump core active wavelength refractive index profile and an annular pump core pump wavelength refractive index profile; and one or more outer claddings disposed about the annular pump core, the one or more outer claddings having an outer cladding active wavelength refractive index profile and an outer cladding pump wavelength refractive index profile; wherein the annular pump core is configured to substantially confine one or more guided modes at the active wavelength in the inner core, said optical fiber amplifying system being characterized in that less than 30% of the intensity distribution at the pump wavelength at the output end of the bridge optical fiber overlaps the inner core of the active optical fiber. an inner core configured to guide radiation of the active wavelength, the inner core having an inner core active wavelength refractive index profile and an inner core pump wavelength refractive index profile; an annular pump core disposed about the inner core, the annular pump core being configured to guide radiation of the pump wavelength, the annular pump core having an annular pump core active wavelength refractive index profile and an annular pump core pump wavelength refractive index profile; and one or more outer claddings disposed about the annular pump core, the one or more outer claddings having an outer cladding active wavelength refractive index profile and an outer cladding pump wavelength refractive index profile; wherein the annular pump core is configured to substantially confine one or more guided modes at the active wavelength in the inner core, said optical fiber amplifying system being characterized in that less than 30% of the intensity distribution at the pump wavelength at the output end of the bridge optical fiber overlaps the inner core of the active optical fiber.