Microwave Emission From Magnetic-Field-Free Electron-Hole Plasmas

Emission is observed only under special plasma conductance conditions. These have been obtained by applying voltages in the form of decreasing steps. Some plasma produced during the initial step remains to produce a higher plasma density during subsequent steps than can be obtained at those lower voltages if they are applied during the initial step. By this means a variety of usually unobtainable conductance conditons have been produced and an approximate threshold curve for the emission has been obtained in terms of current and field strength.