Exploring nonlinear effects in terahertz generation with Hermite–Gaussian chirp pulses under static magnetic fields

Academic research has increasingly focused on the investigation of tunable and energy-efficient terahertz (THz) generation, owing to its significant ramifications across various domains, including crystal structure refinement, military and medical research. This study selects two Hermite–Gaussian (HG) laser beams that exhibit co-propagation and possess chirped frequencies for the purpose of investigation. The laser beam exhibits contact with an undersense plasma that is devoid of collisions when subjected to a static transverse magnetic field. The interaction between laser and plasma exhibits nonlinear characteristics, leading to the production of THz radiation that demonstrates a notable degree of energy efficiency. The objective of this study is to examine the relationship between efficiency of THz conversion, normalised transverse distance, plasma frequency, and additional laser properties such as Hermite polynomial mode index (s) and frequency chirp (b). The results suggest a significant decrease in the effectiveness of THz conversion for normalised THz frequencies in off-resonant situations. The numerical value tends towards zero. An increase in the normalised THz amplitude from 0.0025 to 0.7 and a shift in the peak towards higher normalised transverse distance values are noted as the Hermite polynomial mode index is changed from 0 to 2. The normalised THz amplitude exhibits an observed increase from 0.014 to 0.6 as the chirp parameter is raised from 0.0011 to 0.0099 for s = 1. This study demonstrates the effectiveness of the proposed methodology in generating THz radiation sources that possess high intensity, variable properties, and energy efficiency. The manipulation of the chirped parameter and Hermite polynomial mode index values is employed to accomplish this.