Devices with a double-clad optical fiber and double-clad optical fiber

摘要

The double clad optical fiber becomes, the core of the silica type glass, possessing inside clad and outer part clad. The core, radius under approximately 5 millimicrons, and has 1st refractive index n₁, the active rare earth dopant does not include completely. The inside clad surrounds the core, at least radial thickness of approximately 25 millimicrons, at least approximately 0.25 numerical apertures, and n₂ n1, possesses the 2nd kind of refractive index n_{2 which} becomes. The relative refractive index percent ( %) for the inside clad of the core is larger than approximately 0.1%. Outer part clad surrounds the inside clad, radial thickness, and n of approximately 50 millimicrons₃ n2, possesses the 3rd kind of refractive index n_{3 which} becomes from approximately 10 millimicrons. The relative refractive index percent inside clad for outer part clad (%) is larger than approximately 1.5%.