Resonant Terahertz radiation by p-polarised chirped laser in hot plasma with slanting density modulation

The production of terahertz (THz) radiation via the interaction between lasers and plasmas is an intriguing and swiftly progressing domain of study within the realms of optics and plasma physics. The aforementioned procedure entails the utilisation of high-intensity laser pulses to engage with a plasma, hence leading to the generation of coherent THz radiation. THz radiation, which falls within the frequency range between microwave and infrared, finds utility in various domains such as imaging, spectroscopy, and materials characterisation.This study examines the interaction of two p-polarised, positively chirped laser beams, with a hot collisional plasma characterised by a slanting up density profile. This study investigates the impact of normalised THz frequency, normalised collisional frequency, chirp parameter, and incidence angle of a laser beam on the normalised THz amplitude. The amplitude of the THz signal diminishes fast in off-resonant conditions and tends towards zero as the normalised THz frequency exceeds 1.2. The normalised amplitude of the THz wave falls as the chirp parameter increases from 0.0011 to 0.0099, considering both the normalised THz frequency and the normalised slanting up density modulation parameter. The amplitude of the THz signal, after being normalised, is also influenced by the incident angle and the collisional frequency. In the off-resonant state, the normalised amplitude of the THz wave tends to approach zero when the collisional frequency exceeds 0.8. The objective of this study is to enhance the current knowledge regarding the estimation of the best incident oblique angle, chirp parameter, and collisional frequency to attain an energy-efficient THz source.