Recent advances in high damage threshold diffraction gratings for pulse compression applications - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Communication Dans Un Congrès Année : 2012

Recent advances in high damage threshold diffraction gratings for pulse compression applications

Nicolas Bonod

Résumé

Gratings have been known for more than 2 centuries and have been widely applied in spectroscopy analysis or also communication signal demultiplexing. But they have been used since the mid-80s to compress high power laser pulses in chirped pulse amplification systems and the current development of very ambitious projects of laser chains pushes their limits to a new extent in terms of size, laser induced damage threshold (LIDT) and spectral tolerance. This talk aims to present the recent advances in the development of highly efficiency gratings exhibiting large spectral tolerances and high laser induced damage thresholds.Metallic gratings can offer high reflected efficiencies in a wide spectral range but they suffer from inherent losses that spoil their laser induced damaged threshold. Multilayer dielectric gratings exhibit significantly higher LIDT and the absence of lossy materials permits to provide very high reflected efficiencies but in a narrow spectral window. Developing gratings with low aberration, high efficiencies and high LIDT together with large spectral tolerance remains challenging. I will describe the concept of hybrid metallo-dielectric gratings that appear as good candidates for pulse compression applications since they exhibit high efficiencies over a wide spectral range. The second part of this talk will be dedicated to the current investigation to increase the LIDT of gratings etched onto dielectric materials (hybrid metallo-dielectric gratings or multilayer dielectric gratings). I will evidence the role of the near field enhancement inside the grating on the LIDT and I will show that this enhancement can be significantly minimized by suitably designing the etching profile. More recently, the role played by local microscopic field enhancements due to the presence of electromagnetic waves propagating along the grooves and interfering with the incident pulse has been evidenced. These microscopic enhancements are linked to the roughness of the grating surface and can be suppressed by modifying the incident polarization.
Fichier non déposé

Dates et versions

hal-00734556 , version 1 (23-09-2012)

Identifiants

  • HAL Id : hal-00734556 , version 1

Citer

Nicolas Bonod. Recent advances in high damage threshold diffraction gratings for pulse compression applications. ICUIL 2012, Sep 2012, Mamaia, Constanta, Romania. ⟨hal-00734556⟩
66 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More