Large-aperture chirped volume Bragg grating based fiber CPA system

Abstract

A fiber chirped pulse amplification system at 1558 nm was demonstrated using a large-aperture volume Bragg grating stretcher and compressor made of Photo-Thermal-Refractive (PTR) glass. Such PTR glass based gratings represent a new type of pulse stretching and compressing devices which are compact, monolithic and optically efficient. Furthermore, since PTR glass technology enables volume gratings with transverse apertures which are large, homogeneous and scalable, it also enables high pulse energies and powers far exceeding those achievable with other existing compact pulse-compression technologies. Additionally, reciprocity of chirped gratings with respect to stretching and compression also enables to address a long-standing problem in CPA system design of stretcher-compressor dispersion mismatch.

Volume-chirped Bragg gratings: monolithic components for stretching and compression of ultrashort laser pulses

“…Figure 8(a) shows the dependence of the maximum achievable diffraction efficiency and the minimum achievable scattering losses on the spectral bandwidth of CBGs operating at 800 nm. It is known 12 that an increase in the CBG spectral bandwidth requires a higher spatial refractive index modulation in the PTR glass. The maximum refractive index modulation in PTR glass of ∼10 −3 limits the achievable spectral width to about 20 nm for 800 nm operation.…”

Génération d'un faisceau polarisé gamma à très haut flux par diffusion Compton : l'expérience Mighty Laser

“…Celui-ci consiste en un oscillateur commercial modifié (Origami-10 de Onefive GmbH) délivrant des impulsions laser de 200 fs limitées par transformée de Fourier et cadencées à 178,5 MHz. Afin de limiter les non-linéarités induites lors du processus d'amplification, les impulsions laser sont étirées dans un réseau de Bragg en volume (CVBG de OptiGrate) [14]. Ce CVBG agit aussi comme un filtre spectral, faisant passer la largeur spectrale de 5 nm à 2,2 nm.…”

Volume Bragg Gratings in PTR glass – New Optical Elements for Laser Design

“…This stretched pulse being directed to the same chirped Bragg mirror from the opposite side, would be compressed back to femtoseconds. Such gratins were fabricated and experiment have shown [24,25] that stretching and compression could be performed with efficiency of about 95%. it is beneficial that laser damage threshold of a volume grating is higher than that for surface gratings and this element cannot me misaligned.…”