Combined Effect of Chirp and Exponential Density Ramp on Relativistic Self-focusing of Hermite-Cosine-Gaussian Laser in Collisionless Cold Quantum Plasma

This manuscript presents the dependence of exponential plasma density ramp on relativistic self-focusing of the Hermite-cosine-Gaussian (HcosG) chirped pulse laser in a collisionless cold quantum plasma. Self-focusing along with self-trapping of HcosG chirped pulse laser is studied for different values of laser intensity, decentered parameters, and plasma density. Numerical analysis reveals that these parameters play a key role in achieving the earlier and stronger self-focusing in cold quantum plasma. A comparative study of self-focusing of the HcosG chirped pulse laser with and without exponential density ramp profile is carried out. Exponential ramp profile is found to be more effective in achieving the stronger self-focusing of the HcosG chirped pulse laser. Combined effect of chirp and exponential plasma density ramp on relativistic self-focusing of HcosG laser in a collisionless cold quantum plasma is analyzed, and results reveal the early and strong self-focusing.