Improvement of OOK signals with a polarization-independent feed-forward control circuit using an electro-absorption modulator
An optical-and-electrical hybrid scheme for improving onoff keying (OOK) signals is described. It is a feed-forward (FF) control circuit composed of an optical coupler, a photo-detector, and an electro-absorption (EA) modulator, which works to suppress on level fluctuations. Owing to the use of an EA modulator, the circuit operates irrespective of the polarization state of the input signal. In addition, the scheme can also improve the extinction ratio (ER) of OOK signals. Experiments were conducted to demonstrate the noise suppression and the ER improvement.
ook ea modulator optical communication regenerator