Final Report Summary - NEXTPHASE (NEXT generation of microwave PHotonic systems for AeroSpace Engineering)
The main objective of the project NextPhase was to investigate the performance of microwave photonic oscillators for aerospace engineering. We have in particular led research related to the use of whispering gallery mode resonators in such systems. These resonators have the capability to trap photons for durations that can exceed the microsecond in the near infrared, thereby allowing for narrow-band filtering in the linear regime (< 1 MHz linewidth), and to optical frequency comb generation in the nonlinear regime. We have shown that these resonators can be used to generate ultra-pure microwaves with a phase noise better than -120 dBc/Hz at 10 kHz from a 6 GHz carrier. Using Kerr frequency combs, we have demonstrated as well performances better than -100 dBc/Hz at 10 kHz from carriers with a frequency at up to 50 GHz. We have also shown that these combs have the potential to output signals with a comparable or better spectral purity well beyond the millimeter-wave range. We have therefore proven that these microwave photonic oscillators feature a frequency tunability spanning from the SHF to the THF bands as defined by ITU (from 3 GHz to 3 THz). In the area of optical communications, the project has demonstrated the high potential of Kerr optical frequency combs for ultra-high capacity optical fiber networks. A proof-of-concept experiment permitted to achieve the raw data rate performance of 144 Gb/s per channel using wavelength division multiplexing with an advanced modulation format (16 QAM). Finally, we have developed a compact version of the microwave photonic system which is compatible with the exploitation of the concept in field conditions.