Telecommunication fiber OPA analysis, project and characterization

摘要

Extremely high is nowadays researches interest towards amplification techniques alternative to Erbium Doped Fiber Amplifiers (EDFA); driving force is the exploitation of new and larger fiber optic communication bandwidths. While EDFA gain relies on population inversion in an active material and thus amplification bandwidth is directly related to the doping ion energy levels, well known effects such as Raman and third order nonlinear susceptibility in optical fiber allow amplification not subject to his constraint. In optical parametric amplification, in particular, bandwidth shape and spectral collocation are determined by the choice of pump wavelength and power. Thus almost every spectral region can be reached provided that proper pump is available. We present a detailed analysis of optical parametric amplification in standard communication fiber, discussing different operation regime according to pump wavelength placement with respect to fiber zero dispersion wavelength. In particular attention is paid to the optical parametric amplifier gain bandwidth and saturation. We evidence that a key OPA project parameter is the relative phase between interacting waves, i.e. pump, signal and idler. This parameter not only allows comprehension of gain dynamics in the amplifier, but also can be controlled by engineering the nonlinear medium to improve OPA performances. Experimental verifications are also presented to validate the proposed analysis.