Canova, Lorenzo (2009) Generation and shaping of ultra-short, ultra-high contrast pulses for high repetition rate relativistic optics. PhD thesis physique, Unité Optique Appliquée, EP/X p.193.

Full text available as: - ThèseL-Canova2009.PDF ( 10165 Kb )

Licence: Copyright

Abstract

The ”Physique du Cycle Optique” (PCO) group at the Laboratoire d’Optique Appliqu ́ee (LOA, Palaiseau, France) was created just before the beginning of my Ph.D to study this λ3 regime and in general the possibility of building a kHz, attosecond source based on HHG from solid targets. To reach this goal it is necessary to have a laser source that delivers few-cycle pulses with an energy ≥ 1 mJ. The 1 kHz repetition rate of the laser facilitates detection and char- acterization of the generated harmonics. This source must also satisfy two other important requirements. The first is the temporal contrast (section 2.2.2) which needs to be high enough to prevent uncontrolled pre-ionization of the solid target. The second is the stabilization of the carrier envelope phase (CEP) between successive pulses. The CEP is the shift between the electric field and the envelope of the pulse and influences highly nonlinear effects like HHG process. This kind of source was not commercially available at the beginning of my thesis.

12

The work during my Ph.D was articulated around these requirements. It consisted of using nonlinear pulse shaping to generate high-contrast, few-cycle pulses and to develop new solutions for the CEP stabilization at high energy. The results of this work, done in collaboration with several laser companies like Fastlite, Amplitude Technologies and Femtolasers, are presented in the following chapters. After an introduction to ultra-short pulses and their characterization (chapter 2), in chapters 3, 4 and 5 I present theoretical and experimental results on the third order non linear process called cross-polarized wave (XPW) generation. This nonlinear process is used for generating high contrast, ultra-short pulses. Chapter 6 deals with the development of the CEP stabilized, few-cycle, mJ level laser source (Salle Noire). In chapter 7 I present how this source can be used for high order harmonic generation. In the last chapter (8) I give the prospects for future laser developments in ”Salle Noire” with the integration of an XPW filter in a double CPA configuration and the generation of high contrast, few-cycle, mJ level, CEP stabilized laser pulses.

Statistiques de consultation

Repository Staff Only: edit this item