Pierre-Henri Merrer

Fiber ring resonator based opto-electronic oscillator: phase noise optimisation and thermal stability study

In the microwave domain and among many other advantages, optics represents an elegant solution to increase the quality Q factor in a system. Different types of optical resonators lead to Q factors above 109, and these resonators can be used as an alternative to optical delay lines to set up the frequency in optoelectronic oscillators (OEO). However, microwave-optics is also a complex field, and if the use of optical resonators in high spectral purity frequency generation systems like OEO has been already demonstrated, many aspects of these OEOs are still incompletely understood, especially the contribution to the oscillator phase noise of the different optical and microwave elements used in the oscillator system. In order to improve the phase noise of a fiber ring resonator based OEO, this oscillator has been theoretically studied in term of white frequency noise. In this paper, we present a theoretical study that has lead us to optimize a fiber ring resonator and the experimental phase noise results obtained for an OEO based on an optimized optical resonator. The OEO thermal stability is also investigated in this paper.

Optical techniques for microwave frequency stabilization : Resonant versus delay line approaches and related modelling problems

Optical techniques for microwave oscillators stabilization or microwave sources phase noise measurement are discussed. The advantage in terms of Q factor of optical resonant devices goes with increased difficulties in the system stabilization. System modelling is also complex, because of the interaction of noise sources around three different frequencies : optical, microwave and baseband.