| huiyu1981 |
2010-03-25 15:35 |
Solid-State Random Lasers
This book remindedmeof the unforgettable creative atmosphere in the late 1960s in the laboratory ofmyPh.D. advisor N.G. Basov (at that time already a Nobel laureate in physics, who shared the prize in 1964 with A.M. Prokhorov and C.H. Townes). One of the experimental groups at that time includedV.S. Zuev, P.G. Kryukov, and R.V. Ambartsumyan, who were working on an exceptionally important problem e1 '_]
of amplifying nanosecond pulses in a cascade of ruby amplifiers to ignite a nuclear fusion reaction. I collaborated with this group trying to understand the challenging problems and questions that arose in the process of the experiments. One such problem, related to the strange behavior of a nanosecond pulse in a chain of amplifying crystals, led to the discovery of nonlinear propagation of a front of #~ >0Dr
amplified pulse with a speed greater than the speed of light. A simpler problem, self-excitation of stimulated emission in a cascade of amplifiers by examination of its output with a paper white card, led to the concept of nonresonant intensityfeedback without conservation of a phase. At the same time, I realized that this effect takes place in a medium with distributed amplification and scattering if thephoton scattering length is significantly smaller than the gain length. In such a medium, there exists an effect of self-confinement of light, which is characterized by a stimulated emission threshold and many other properties of regular lasers, but without spatial coherence of radiation. lFRgyEPH
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