|Author||Bukhman, N. S.|
|Source||United States Department of Energy Office of Scientific and Technical Information|
|Subject Keyword||CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ABSORPTION ♦ AMPLITUDES ♦ CARRIERS ♦ FREQUENCY MODULATION ♦ GAIN ♦ LASER RADIATION ♦ REFRACTIVE INDEX ♦ SIGNAL DISTORTION ♦ SIGNALS ♦ SYMMETRY ♦ VELOCITY ♦ AMPLIFICATION ♦ ELECTROMAGNETIC RADIATION ♦ MODULATION ♦ OPTICAL PROPERTIES ♦ PHYSICAL PROPERTIES ♦ RADIATIONS ♦ SORPTION|
|Abstract||It is shown that, when a narrow-band signal with a non-Gaussian envelope propagates in a medium with a strong dispersion, the signal envelope being distorted due to the dispersion of the gain (or) absorption in the medium. Nevertheless, the amplitude-modulated signal having a symmetric (even) intensity envelope remains the same. The propagation velocity of the 'middle point' (i.e., the symmetry centre) of the signal coincides with the real group velocity of the wave with a given carrier frequency in the medium and can be subluminal, superluminal or negative. Therefore, the concept of a real group velocity (including the superluminal or negative velocity) is also applicable in media with a strong dispersion of the gain (or absorption). (interaction of laser radiation with matter. laser plasma)|
|Learning Resource Type||Article|
|Publisher Place||United States|
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