Estimation of Erbium Doped Optical Fibers Effective Area

Erbium doped fiber amplifiers (EDFAs) are one of the most extensively used optical amplifiers in the fiber optics transmission systems. EDFA working principle is based on erbium doped fiber (EDF) application to amplify optical signal at wavelength region used in telecommunications. Optical amplification is related with high optical signal power and therefore high optical radiation intensity in the fiber. Due to optical fiber nonlinear characteristics at high optical intensity nonlinear effects can occur in EDF simultaneously with amplification. To assess nonlinear effects in the fiber very important parameter is an optical intensity that depends on input optical power and fiber effective area Aeff. The aim of this research is to estimate EDF Aeff changes at different input optical radiation wavelength and power levels to study optical intensity changes. Measurement setup (Fig.1.) consists of tunable laser source, micro-positioner, optical power meter and fiber under test. Measurements were performed at different optical radiation wavelengths that are characteristic to EDFA operation: 980nm and 1480nm as erbium excitation wavelength and couple wavelengths from EDFA amplification range from 1520nm to 1630nm. Each measurement was performed at three different optical power levels 8, 10 and 12 dBm. The measured values of the fiber effective area are in the range from 49.50μm2 at λ=980nm and Pin=8dBm to 76.34μm2 at λ=1630nm and Pin=12dBm. It was found out that for 980nm measured effective area is considerably smaller than for other wavelength. IEEE Catalog Number: CFP1130R-USB ISBN: 978-1-4577-1876-