ECOC19 – RFSA

Awareness about the use of network assets and spectral resources in particular requires continuous and seamless monitoring throughout the network. Dense network architectures with high dynamicity in its highly populated links call for a distributed rather than a centralized approach so that the respective monitoring functionality should be integrated in all network terminals. In order not to introduce additional cost, we propose to re-use a transmitter that is widely adopted in directmodulation / direct-detection systems as a spectral monitor. We experimentally demonstrate that an externally modulated laser is offering the functionality of a continuously tunable coherent receiver in order to down-convert optical signals to the RF domain for subsequent narrowband slicing and power integration. Modulation spectra for on-off keyed signals at different data rates and pulsed signals can be correctly acquired over a spectral range of 320 GHz, in virtue of the high resolution that the proposed coherent spectrum analyser is offering. The errors in wavelength and magnitude are less than 36 pm and 4.6 dB, respectively.