The Bloch-Maxwell Super-Radiance Quantum Optical Model

John M. Arnold

Roy J. Glauber

M. G. Benedict, A. M. Ermolaev, В. А. Малышев +2 more

This chapter introduces a three-level atomic model and discusses two other coherent atomic phenomena; namely, coherent Raman scattering and lasing without inversion. Lasing without inversion may take place in three-level resonant atomic systems and, like super-radiance, results from atomic coherence. Super-radiation is initiated by spontaneous fluctuations of the polarization in the medium. The semiclassical method is a powerful tool that is useful for the treatment of propagation effects in super-radiance as well as in such coherent emission processes as self-induced transparency, photon echo and others. The use of the Maxwell—Bloch equations allows one to consider these phenomena in elongated systems. Fortunately, the semiclassical approach is readily applicable to low-density systems that are to gases. However, one has to exercise greater care when applying it to coherent emission in solids. In high-density systems there is a strong mixing of the field and atomic states in the vicinity of resonance.

M. G. Benedict, A. M. Ermolaev, Viktor A. Malyshev +2 more

This chapter is devoted mainly to the description and theoretical interpretation of super-radiance experiments in a multi-proton spin system. It considers the simplest case of multi-spin super-radiance in a cavity. The spin magnetic moment in a static magnetic field is a perfect realization of the 'two-level' atomic model. In fact, this physical system was the origin of this model, and was extended to a wide class of resonant phenomena, including super-radiance. A refined description of super-radiance of magnetic spins in solids will probably have to take into account the dependence of the relaxation rate on the magnitude of the magnetization, using as a basis the concept of spin temperature. The chapter shows the limitations of the method of Bloch equations for describing NMR effects in solids, as mentioned earlier in the literature. It attempts to observe super-radiance in the radiofrequency domain was reported by P. Bosiger and their group, using a nuclear subsystem of Al atoms in ruby crystals.

Franco Gori

Hideaki Hara, Junseok Han, Yasutaka Imai +5 more

We observed periodic optical pulses from an Er:YSO crystal during irradiating with an continuous-wave excitation laser. We refer to this new phenomenon as "periodic super-radiance". This periodicity can be understood qualitatively by a simple model, in which a cyclic process of a continuous supply of population inversion and a sudden burst of super-radiance is repeated. The excitation power dependences of peak interval and the pulse area can be interpreted with our simple model. In addition, the linewidth of super-radiance is much narrower than an inhomogeneous broadening in a crystal. This result suggests that only Er3+ ions in a specific environment are involved in super-radiance.