THE ORIGIN OF EXCESS NOISE

The key features of excess noise are reviewed and the results illustrated using a confocal strip resonator example. The excess noise factor (Or Petermann K factor) is shown to be a strong function of the effective Fresnel number of the resonator; for Fresnel numbers in the region of 50, peak values of K are greater than 10(4). The identity between the excess noise factor and the injected-wave excitation factor is demonstrated numerically, and both mathematical and physical interpretations of the high values offered.