Photon statistics of a two-photon laser

M. P. Sharma, P. R. P. Silva

A. Bandilla, H. Voigt

M. M-Tehrani, L. Mandeļ

T. Yu. Golubeva, Yu. M. Golubev, D. A. Ivanov

The statistical properties of light emitted by a three-level laser are theoretically investigated. In the model considered the three-level medium is coherently excited by another laser having arbitrary photon statistics. It is shown that under certain conditions the photon statistics of the three-level laser is determined by that of the exciting laser. This feature is referred to as induced photon statistics. It is proposed to use this phenomenon to analyze the statistics of a laser involved in a feedback process. Arranging an experiment in a way such that the laser of interest serves as a coherent pump for the probe three-level laser one is able to directly observe the statistics of the feedback-controlled laser by simply detecting the induced photon statistics in the three-level probe system. The analysis of the operation of such two-laser system presented demonstrates, in particular, that the feedback itself is unable to produce a nonclassical state of light which is in complete agreement with the conclusion of Wiseman and Milburn [Phys. Rev. A 49, 1350 (1994)].

IMRANA, ASHRAF

In this dissertation, we study the quantum theory of two-photon micromaser and laser. To begin with, we study the photon statistics of the two-photon micromaser by considering the interaction of a quantized single-mode field with an effective two-level atom through intermediate states. We present an exact solution for the photon distribution function and study the behaviour of mean photon number and photon number fluctuations. A periodic "collapse" and "revival" type behaviour is predicted. We find that the photon number fluctuations exhibits a periodic sub-Poissonian behaviour with respect to the interaction time. We then discuss the photon statistics of two-photon laser and derive an exact expression for photon distribution function. We find that photon distribution function for two-photon laser is wider than the Poisson distribution function. We also calculate the natural line-width of a two-level two-photon laser by using a Fokker-Planck approach. It is shown that, apart from a constant, the gain contribution to the laser linewidth is equal to the two-photon gain parameter and is independent of the mean number of photons in the field. Finally, we study the two-photon transitions in multi-level atomic system. In this case first we discuss the photon statistics of three-level two-photon micromaser and laser. Then we consider the two-photon transition in four-level atomic system by considering dye laser as an example.

C. W. J. Beenakker