太赫兹波在时变等离子体中的频谱变化OA

When a hypersonic aircraft flies in near ground space,the air around the aircraft is ionized to produce plasma.The plasma around the aircraft causes electromagnetic waves to reflect and attenuate,making it impossible for the aircraft's receiver to receive exter-nal signals,thus forming a"blackout"phenomenon.The propagation of terahertz waves in plasma is of great significance in addressing this issue.Due to the temporal variation of electron density in plasma,terahertz pulses in plasma with different electron density rise times and maximum electron density values are calculated by the numerical method.The results reveal the impact of rapidly generated plasma on the terahertz wave spectrum.It is indicated that when the rise time of the electron density is less than or equal to the terahertz wave pe-riod,the time-varying characteristics of the rapidly excited plasma is significant,causing the phenomenon of terahertz wave spectrum changes.