Cascaded Four-Wave Mixing for Microwave Photonic Harmonic Multiplication

Enhanced multiple four-wave mixing (FWM) processes in nonlinear fiber by phase modulation of the pump carrier are investigated for harmonic mixing multiplication of microwave signals. The enhancement of cascaded FWM by phase modulation in the case of small spacing between pump carriers (10 GHz) is studied. Experimental results show that microwave signals in the V-band can be generated from a tone in the C-band through external amplitude modulation and optical nonlinear harmonic multiplication. A harmonic multiplication factor of 13 has been demonstrated using the proposed technique. The upconverted microwave signals show no additional degradation in phase noise due to the photonic nonlinear processes besides the inherent phase noise increment due to the multiplication process.