Diagnostic results of new-generation dispersive element test samples based on Bragg structures in fused silica

A comprehensive diagnostics of new-generation dispersive elements based on Bragg structures was completed. The influence of inscription parameters on the properties of samples was studied and a threshold inscription intensity of ~ 6.38 TW/cm2 at which the linear absorption coefficient as well as the phase and polarization stresses sharply increase was found. When inscription is made with an average intensity below the threshold, the linear absorption in dry silica samples remains at a level of 10-5 cm-1, which is approximately two orders of magnitude lower than that of currently available commercial samples. The measured values of the dispersion characteristics using a white light interferometer coincided are in a good agreement with the calculated values provided by the manufacturer. The results of the diagnostics show that the new-generation dispersive elements are promising for compressing kilowatt-level radiation of average power.