Čerenkov radiation excited by an ultrashort laser pulse with oblique amplitude front

We develop the theory of generation of terahertz ?erenkov radiation in a homogeneous nonlinear optical crystal if the amplitude and phase fronts of the excitation pulse do not coincide. It is shown that in the case of the nonlinear optical interaction, the use of laser pulses with oblique amplitude front makes it possible to increase the efficiency of generation of terahertz radiation. In contrast to the case where the amplitude and wave fronts coincide, radiation propagates in a strictly determined direction specified by the amplitude-front plane. It is established that the maximum generation efficiency is reached if the angle of inclination of the amplitude front coincides with that of the terahertz-radiation wave vector.