The microscopic maser

Hans Motz

L. A. Lugiato, Marlan O. Scully, HERBERT WALTHER

We show that the steady-state photon-number distribution of the microscopic maser can be recovered using the standard macroscopic quantum laser theory. We introduce an appropriate limit of weak pump and weak photon damping to make the connection between the microscopic and the macroscopic quantum theory of laser operation. Simple analytic formulas describe the main features of the stationary photon-number distribution in the microscopic maser.

P. Filipowicz, Juha Javanainen, Pierre Meystre

We present the theory of a truly microscopic maser consisting of a single-mode high-Q resonator in which a monoenergetic beam of excited two-level atoms is injected at such a low flux that at most one atom at a time is present inside the cavity. Both a microscopic theory and a heuristic Fokker-Planck approach are presented. We show that the micromaser exhibits a number of novel features that are averaged out in usual masers and lasers. First, the field is in general sub-Poissonian, which reflects the quantization of both the field and its sources. Second, the onset of maser oscillations may be followed by a succession of abrupt transitions in the state of the field. Finally, as the atomic flux through the resonator is increased, the maser threshold acquires characteristics of a continuous phase transition, whereas the subsequent changes in the field distribution become analogous to first-order phase transitions.

Noriaki Horiuchi

G. S. Agarwal

We show that laser and maser action is possible using atoms that have been prepared in dressed states. We develop the microscopic theory and derive the Fokker-Planck equation for the field distribution for such a laser (maser) system.

JOHN C. MORRISON