A model of cavity radiation is proposed in which the stimulated emission is modelled as an age-dependent birth process. The photon population statistics, under certain special conditions, are shown to possess thermal characteristics to second order.
Some of the implications of non-Markov evolution of cavity radiation and its detection are examined. The cavity photons are modelled as members of a population governed by a Bellman-Harris process supported by immigration. Further it is assumed that there is a detector near the cavity and the photosensitive atoms of the detector absorb the photons with a uniform probability η per unit time. Explicit expressions for the first two moments of the equilibrium cavity distribution are provided. A general formula for the spectral profile is also given. The Markov model of Shepherd is recovered as a special case. A detailed analysis is provided for a special case in which the photon is assumed to go through two hypothetical phases before it gives rise to cavity absorption or stimulated emission. A noteworthy feature is the persistence of bunching, although the bunching is less than that of chaotic light.
The population model of cavity photons previously introduced is analysed by identifying the non-Markov evolution in terms of phases whose durations are themselves independent and exponentially distributed random variables. The resulting radiation is shown to have thermal characteristics for an appropriate choice of the population parameters. The detection process is explicitly introduced and its characteristics are obtained. The model is shown to be viable enough to produce intensity spectra of different shapes corresponding to the resulting radiation.
A detailed analysis is provided of a non-Markov model of cavity population in which each emission gives rise to a random dead-time during which no further emissions can take place. Differential equations are derived for the generating functions governing the cavity population size. The moment structure of the population size is examined and explicit expressions for the first two moments are provided. The photon population statistics are shown to be antibunched for a wide choice of the population parameters. The detection process is analysed and an explicit expression is provided for the Hanbury Brown-Twiss type of correlation. It is further shown that an appropriate choice of the population parameters can produce a thermal stream with Lorentzian profile.
A non-markovian model of the detection of cavity photons is proposed. The cavity photons interact with the atoms of the detector in a two-stage process, while the evolution of the cavity photons is modelled, as usual, as a population process with constant rate parameters. The joint distribution of the cavity photons and the number of detected photoelectrons is studied. The results corresponding to the markovian model proposed by Shepherd are recovered by an appropriate limiting procedure. Some simple characteristics of the twofold counting statistics are also obtained. In particular, the memory effects of two-stage detection are shown to result in a depletion of bunching; the shape of the spectrum (in the time domain), while similar to that obtained using the Shepherd model, is depressed pointwise by a memory-dependent factor.