Dual Comb Spectroscopy from IR and XUV Application

Abstract

In this thesis, we utilized dual comb spectroscopy to demonstrate broadband, high resolution and time-resolved measurement in a LIBS (laser-induced breakdown spectroscopy) for the first time. It is enable to investigate time resolve dynamics and monitor multiple species simultaneously. As a first demonstration, we simultaneously detect trace amounts of Rb and K in solid samples with a single laser ablation shot, with transitions separated by 5 THz (10 nm) and spectral resolution sufficient to resolve isotopic and ground state hyperfine splittings of the Rb D2 line. This new spectroscopic approach offers the broad spectral coverage found in the powerful techniques of laser-induced breakdown spectroscopy (LIBS) while providing the high-resolution and accuracy of cw laser-based spectroscopies. In order to extend dual comb spectroscopy to the VUV and XUV region, We implemented a fully phase-coherent dual comb spectroscopy consisting of two identical enhance-cavity for high harmonic generation (IHHG) systems operating in parallel. This system is developed for XUV dual comb spectroscopy based on two high power ytterbium fiber laser system using parabolic amplification scheme to achieve sub-80fs after amplification up to 60W of average power with 80MHz repetition rate. Furthermore, we have demonstrated the development of a novel pump-probe technique using the enhancement cavity that allowed a direct measurement of the intracavity plasma and its decay dynamics in real-time.