The Effect of Pulse Duration, Laser Energy, and Gas Pressure on High Harmonic Generation Efficiency and Spectral Characteristics

Abstract

This Bachelor’s thesis investigates the role of pulse duration, laser energy, and gas pressure on the efficiency and colour of the High Harmonic Generation (HHG) process. HHG is a nonlinear optical phenomenon that generates extreme ultraviolet (XUV) radiation when an intense laser beam interacts with a material. XUV radiation is characterized by high photon energies and short wavelengths, making it useful for a wide range of applications in science and technology, such as imaging, spectroscopy, and microscopy.

The study is conducted using a laser system that generates femtosecond laser pulses, which are focused onto a gas target to generate XUV radiation. The energy and spectrum of the generated XUV radiation are analyzed for different values of pulse duration, laser energies, and gas pressure values, as well as the effects of using gas cells of different lengths and gap diameters.

The results show that changing the pulse duration and laser energy have a significant effect on the energy of the XUV photons and photon flux, while the gas pressure has a minor effect. Moreover, the use of gas cells of different lengths and gap diameters also affected the energy of the XUV photons and photon flux. The findings of this study have important implications for the design and optimization of HHG systems for various applications, including the development of more efficient and versatile XUV sources that can contribute to the advancement of various fields of science and technology.