Optical automatic gain control of EDFA using two oscillating lasers in a single feedback loop

A novel configuration for automatic gain control of optical amplifiers is presented. It uses a F-P filter with 26.7 nm free spectral range and two long-period gratings (LPGs) to produce two lasing wavelengths in a single feedback loop. By bending the LPGs, the cavity losses at different wavelengths can be varied independently to achieve single and two oscillating lasers control conditions. The experimental result suggested that the simple configuration could be employed to significantly reduce the surviving channel steady-state and transient power excursion.