HfO2/SiO2 chirped mirrors manufactured by electron beam evaporation

Appl Opt. 2011 Mar 20;50(9):C388-91. doi: 10.1364/AO.50.00C388.

Abstract

A HfO2/SiO2 chirped mirror was manufactured by electron beam evaporation to increase the laser resistance. The hybrid monitoring strategy utilizing both monochromatic monitoring and quartz crystal monitoring was applied to the deposition compared to the single optical monitoring method. The coatings were characterized by transmission spectrophotometer and white light interferometry, and the experimental results showed that the chirped mirror monitored with the hybrid strategy possessed high reflectivity (>99.7%) and tolerable group delay dispersion oscillation (-50±20 fs2) in the spectra range of 740-860 nm.