A systematic study of how the erbium-doped fiber amplifier (EDFA) gain behaves inside an active recirculating delay line structure is presented. It is verified using a representation of an active-fiber Bragg-grating-pair filter. It shows that due to the presence of the recirculating signal, the EDFA gain inside the cavity exhibits hard saturation, and with a proper design, fluctuations in pump power have only slight effects on EDFA gain and this enables the active delay line filter to realize a stable high-Q frequency re- sponse. Results demonstrate a high-Q photonic signal processing filter that exhibits low sensitivity to pump power perturbations and which shows robust active filter operation.
|Number of pages||3|
|Journal||IEEE Photonics Technology Letters|
|Publication status||Published - Oct 2004|