Electromagnetically induced transparency and pulse propagation in plasmas

Summary from only given. Electromagnetically induced transparency (EIT) is a process in which a low frequency electromagnetic wave (below the plasma frequency /spl omega//sub p/) propagates essentially unattenuated in the presence of a high frequency wave (above /spl omega//sub p/) (Harris, 1996). In EIT the nonlinear plasma current that arises from the beating of the waves cancels the linear plasma current. A narrow bandpass region, below /spl omega//sub p/, exists when the frequency difference between the wave is close to /spl omega//sub p/. The bandpass region consists of nonlinear modes having positive and negative group velocities. We present a general analysis of EIT that is based on the interaction of three EM waves, representing the pump, the Stokes and the anti-Stokes waves, along with a plasma wave. Based on the nonlinear dispersion relation we discuss the propagation characteristics of the waves inside the plasma. Numerical solutions are presented that illustrate the conditions under which propagation of the Stokes wave in the plasma is possible.