Patent ID: 6816652
Filing Date: 2004-11-09
Classification: G02B,H01S

Abstract:
A fiber device, comprising:a sleeve having an elongated tubular body with an input terminal and an output terminal; an input fiber ferrule placed in said sleeve at said input terminal; a plurality of pump fibers bundled together at one fiber terminals by said input fiber ferrule to form a pump fiber bundle, wherein end facets of said bundled fiber terminals are polished to form an optical pump coupling surface for outputting pump light from said pump fibers; a plurality of lasers respectively coupled to said pump fibers to produce light into each pump fiber; an output fiber ferrule placed in said sleeve at said output terminal; a double-clad fiber having a fiber core, an inner cladding layer surrounding said fiber core, and an outer cladding layer surrounding said inner cladding layer, said double-clad fiber further including a pump-receiving terminal coupled to said output fiber ferrule to receive said pump light into said inner cladding layer, wherein said double-clad fiber includes a fiber loop in which said fiber core in doped with active ions to produce optical gain; a lens disposed in said sleeve between said input and said output fiber ferrules to image said optical pump coupling surface onto said pump-receiving terminal, wherein said lens has a numerical aperture not greater than a numerical aperture of said inner cladding layer; a first set of wavelength-selective reflectors formed in said double-clad fiber between said pump-receiving terminal and said fiber loop, each reflector operable to reflect light at a selected wavelength while transmitting light at other wavelengths; and a second set of wavelength-selective reflectors formed in said double-clad fiber on a side of said fiber loop opposite to said first set of wavelength-selective reflectors, each reflector operable to reflect light at a selected wavelength while transmitting light at other wavelengths.