Noise reduction technique for cladding pumped optical amplifiers

摘要

Systems and methods for suppressing cladding modes at the signal wavelength in an optical fiber system utilizing an optical amplifier without perturbing the pump wavelength. An outer cladding of the gain fiber is removed providing a short section of a single mode fiber that does not guide the higher order modes, thus attenuating the higher order modes. Therefore, this system eliminates unwanted noise. In an embodiment, the modes are filtered at the end of the gain section of the optical fiber before splicing to an input fiber. Hydro florate etching can be utilized to remove the outer cladding. The resulting fiber maintains fundamental mode propagation and no mode mixing occurs while losing the higher order modes eliminating the noise.