Rare earth doped double clad optical fiber with plurality of air holes and stress rods

摘要

An optical fiber including: (i) a silica based, rare earth doped core having a first index of refraction n₁; and (ii) at least one silica based cladding surrounding the core and having a second index of refraction n₂, such that n₁>n₂, said cladding having a plurality of stress rods and a plurality of air holes extending longitudinally through the length of said optical fiber; wherein said optical fiber supports a single polarization mode or poses-polarization maintaining properties within the operating wavelength range.