Approximate photon distribution in lasers

Yucheng Hu, Xiang Peng, Tiejun Li +1 more

C. W. J. Beenakker

Reeta Vyas, Surendra Singh

The effect of counter-rotating terms in the interaction Hamiltonian on the photon statistics is investigated for a single-mode laser. The treatment is based on the Scully-Lamb model. A perturbation expansion is used to derive an equation of motion for the field-density matrix. The counter-rotating terms are found to lead to both transient and secular effects. With some reasonable approximations the steady-state photon-number distribution is derived and it is shown that the counter-rotating terms tend to raise the threshold of laser action and broaden the photon-number distribution. The relative size of these effects is found to be very small and depends on the square of the ratio of the atomic linewidth and the transition frequency.

G. Dattoli, Juan Carlos Gallardo, Alberto Renieri +1 more

In a recent paper of Lee [Phys. Rev. A 31, 1213 (1985)], it was stated that the photon-number distribution in a free-electron laser is always sub-Poissonian. This statement is clearly in contradiction with well-known published results. We show that in the recoilless approximation the photon statistics is Poissonian. However, for electron recoil different from zero, the photon-number distribution presents bunching (antibunching) for positive (negative) detuning parameter.

L. Z. Wang, Shi-Yao Zhu

G. Dattoli, Juan Carlos Gallardo, Alberto Renieri +1 more

A recent paper stated that the photon-number distribution in a free-electron laser is always sub-Poissonian. This statement is clearly in contradiction with well-known published results. In the recoilless approximation the photon statistics is Poissonian. However, for electron recoil different from zero, the photon-number distribution presents bunching (anti-bunching) for positive (negative) detuning parameter.