High capacity passive optical network monitoring scheme using self-seeding Fabry–Pérot laser diode with direct modulation

We propose and experimentally demonstrate a high capacity optical monitoring scheme using a self-seeding Fabry–Pérot laser diode (FP-LD) with direct modulation in a passive optical network (PON). A simple, stable, and low-cost monitoring source with side mode suppression ratio of 47 dB that consists of a FP-LD, a polarization controller, and a fiber Bragg grating is presented. The detecting signals can be encoded in two-dimension, i.e., pulse widths and wavelengths, which is very suitable for high capacity PON monitoring. The final recognition process is very simple because only the rectangular pulse width needs to be identified, especially compared with the complicated network recognition algorithm.