Modulation of radiation in an active medium due to modulation of pumping at microwave frequencies

An analysis is made of the dynamics of modulation of a light signal in an active medium pumped by an electron beam modulated at microwave frequencies. The quasisteady approximation is used to find the relationship between the velocities of propagation of maxima of the light signal and of the pump wave, and also the relationship between the depth of modulation of the light signal and the repetition frequency of the pump pulses. Numerical calculations are used to analyze the propagation of light ($\lambda= 430$ nm) in an He–Sr mixture pumped by pulses of $f=500$ MHz frequency with an average current density $\bar j= 5$ A/cm$^2$. It is shown that deep modulation is possible.