Noise predictions for optoelectronic oscillators using different models

In this paper an optoelectronic oscillator (OEO) is analyzed with two different approaches. The two approaches lead to two models which allow prediction of the oscillator phase noise on the basis of the noise of its components. The first method, called Leeson's method, applies control system theory to an oscillator described by functional blocks. The second, called Van der Pol's method, uses the time domain equation of the oscillator, which is linearized about an equilibrium under the assumption of slow variations of the state variables. In both cases the predicted noise is compared with the measured noise of a real OEO.