TRAPPING OF AN ELECTROMAGNETIC-WAVE BY THE BOUNDARY OF A TIME-VARYINGPLASMA

The interaction of an electromagnetic wave with a plasma half-space wh ose density instantaneously grows in time due to ionization processes is considered. Unlike previous works in this field treating the degene rate case of normal incidence, oblique incidence of a TM polarized wav e on the plasma boundary is investigated. A distinguishing feature of the case of oblique incidence is the creation of two frequency downshi fted surface waves propagating along the plasma boundary in the opposi te directions. Their frequency shifts and amplitudes as well as charac teristics of the other steady-state modes are examined. Angular and fr equency distributions of outgoing transient radiation are discussed. I n particular, we have shown that the frequency upshift of the generate d transients can be higher than for the normal incidence case reported earlier. The results are presented for both gaseous and solid-state p lasma.