Conversion gain characterisation of optical radiofrequency signal mixing by all-optical sampling based on SOA-MZI
Résumé
Using an optical network to transmit radiofrequency signals (radio over fibre) naturally leads to implementation functions, such as frequency mixing, directly in the optical layer. Proposed is an all-optical sampling method based on a SOA-MZI to frequency upconvert an electrical subcarrier at 1 GHz up to 38 GHz. The optical pulsed source used to sample the electrical subcarrier generates 21 ps-width pulses at a repetition rate of 7.8 GHz. Although the SOA-MZI bandwidth is limited to 7 GHz, frequency upconversions up to five times the 7.8 GHz sampling rate have been evaluated through the conversion gain. Its value lies between 14.4 to -20.3 dB depending on the frequency to be reached.