У даній роботі подано приклад розрахунку коефіцієнта поглинання у термінах квантової оптики, враховуючи ефект Допплера. Отриманий вираз для локальних значень коефіцієнта поглинання, оснований на комутаційному співвідношенні між операторами електричного поля та інтенсивності, нелінійно залежить від атомної густини та початкової інтенсивності.
In this work the calculation method of absorption coefficient in the terms of quantum optics, taking into account the Doppler effect, is presented. The atomic collisions are not discussed here. Accordingly, in contrast with the impact theory, the introduction of the chronology of absorption/reemission events in the system is avoided here. The "single-atom" methods, such as the equation of motion for the one-particle population matrix, to find the number of quanta, imbibed by atoms or liberated into the environment per unit time, are not used here. Under certain assumptions, it is enough to know the information about the distribution of system states at the giveninitial moment of time for the calculation of the coefficient of absorption. The derived expression for the local absorption coefficient, based on the commutation relation between the operators of electric field and intensity, non-linearly depends on& atomic density and initial intensity. It was found that the ability of the system to absorb or emit quanta can quantitatively be expressed through the special form of interaction integrals. The form of dependence on the integrals results from the st&ructure of the quantum brackets.
