Internal and external field fluctuations of a laser oscillator: Part II--Electrical circuit theory

The amplitude and phase noise spectra of the internal and external fields of a negative resistance oscillator are derived using electrical circuit theory. It is shown that the difference between internal and external fluctuations becomes important in the quantum domain ( ) where external noise sources are not negligible as they often are in the classical domain ( ). Using established methods to describe quantum fluctuations in electrical circuits, we obtain results in full agreement with the more exact but less general direct quantum mechanical analysis of a Fabry-Perot laser in Part I.