Efficient cross polarized wave generation for compact, energy-scalable, ultrashort laser sources

L P Ramirez,P Georges,R Lopez-Martens,A Ricci,P Monot,D N Papadopoulos,F Druon,J P Rousseau,A Jullien,X Chen,A Pellegrina

doi:10.1364/oe.19.000093

Abstract

The generation of high contrast and ultrashort laser pulses via a compact and energy-scalable cross polarized wave filter is presented. The setup incorporates a waveguide spatial filter into a single crystal XPW configuration, enabling high energy and high intensity transmission, efficient contrast enhancement and pulse shortening at the multi-mJ level. Excellent XPW conversion of up to 33% (global efficiency: 20%, intensity transmission: 40%) led to an output energy of 650 µJ for an input of 3.3 mJ. Additionally, efficient conversion under specific input phase conditions, allowed pulse shortening from 25 fs to 9.6 fs, indicating the prospective application of this setup as a high energy, ultrabroad laser source.

Highlights

Cross polarized wave generation (XPW) is a well established technique for contrast enhancement of ultrashort pulses in high energy laser systems
We demonstrate efficient XPW generation (33%) with high energy input pulses up to 3.3 mJ
We observe that in general, reasonable conversion efficiencies (>20%) are obtained effortlessly for a wide range of spectral phase values because with the waveguide filter, we can approach the theoretical efficiency of a single crystal XPW setup

Summary

Introduction

Cross polarized wave generation (XPW) is a well established technique for contrast enhancement of ultrashort pulses in high energy laser systems. Efficient conversion with XPW only occurs at high intensities. Single crystal setup, multi-mJ input energies could be used either by utilizing long focal lengths (>10 m) or working out of focus. Both solutions have tradeoffs: the first resulting to a bulky, extended setup while the second may lead to hotspots in the incident beam profile which is unfavorable for XPW, limiting the internal conversion efficiency to the order of 10-15% [2]. For multi-mJ pulses, the crystal distances lengthen to tens of meters, resulting in complicated and cumbersome configurations

Methods

Results

Conclusion