Rare earth doped single polarization double clad optical fiber with plurality of air holes

摘要

An optical fiber including: (i) a silica based, rare earth doped core having a first index of refraction n₁; (ii) a silica based inner cladding surrounding the core and having a second index of refraction n₂, such that n₁n₂, said inner cladding having a plurality of air holes extending longitudinally through the length of said optical fiber; (iii) a silica based outer cladding surrounding said inner cladding and having a third index of refraction n₃, such that n₂n₃, wherein said optical fiber supports a single polarization mode within the operating wavelength range.